Prove that for all positive integers $n$, $\sum_{k=1}^{n}(-1)^kk!S(n,k)=(-1)^n$

Prove that for all positive integers $n$, $$\sum_{k=1}^{n}(-1)^kk!S(n,k)=(-1)^n$$ where $S(n,k)$ are the Stirling numbers of the second kind. I recognize that $k!S(n,k)$ is the number of surjections from an n-element space to a k-element space. I think there might be some kind of symmetry as well, but I am unsure how to evolve this thought into the proof. For instance, $$k!S(n,k) = 1 \text{ for } k=1 \text{ and }k=n$$


I ran the following command in chroot environment without X:  gsettings set org.gnome.desktop.a11y.applications screen-reader-enabled true  I get the following error message:  (process:8290): WARNING **: Command line `dbus-launch --autolaunch=09be9504960407430fb3a253000052a5 --binary-syntax --close-stderr' exited with non-zero exit status 1: No protocol specified\nNo protocol specified\nAutolaunch error: X11 initialization failed.   Is X a must for changing gsettings? Is there another way to change the setting? (My purpose is to make a LiveCD iso with screen reader enabled by default)  Thanks!


BASH variable name containing number issue

Running in some trouble using a variable with a number..   This works;  sourceid_2="blah" echo $sourceid_2   But this doesnt work;  sourceid_2="blah" i=2 echo $sourceid_$i   Any ideas how to fix this? I tried without the underscore.. but that didn't help.   My end goal is to do something with the variable in a for i in {2..7} loop.. like this;  for i in {2..7} do echo $sourceid_$i done


How to run automatically Docky at lubuntu?

in general: How can I make an application automatically start when I have logged in?


British placement of punctuation relative to inverted commas

I already found many related questions, but no sourced and exactly fitting answers, so I have to ask again.  I know there are different standards. I am interested in the British one. I was under the impression that punctuation was to be enclosed within the inverted commas, if and only if it formed part of the utterance. To my understanding, the following sources corroborate my statement (please note the position of the bold face comma):    Example from it:     ‘Economic systems’, according to Professor White, ‘are an inevitable byproduct of civilization, and are, as John Doe said, “with us whether we want them or not”’.     Edit: This one seems to be wrong. Unfortunately, I followed it for months.   Example from it:     "Hello", he said. "How are you today?"   Shockingly, it appears that the following contradicts my interpretation:   namely in the examples:     ‘You’re right,’ he said.   and     ‘I don’t agree,’ I replied.   Am I overlooking something? Is the standard changing? I am very confused!


XS sounds like excess, B4 sounds like before, XLNC sounds like excellency, etc.  What are these wordplays called?


What are the syllabification rules for English?

I am trying to break a word down into syllables and am not quite sure how to do it for English. Some problems I face:     The letter-to-sound rules are not one-to-one. As an example, notice that z"ea"l and "ee"l are different in orthography but map to the same sounds.   English has a large number of foreign words incorporated into it, which makes "sticking" to a certain set of rules all the more difficult.    So my question is: 1. Are there any definite rules for breaking a word in English down into its constituent syllables (CV, CVV, CCV etc.?). 2. What is the "gold-standard" (something used by a majority of the community) on this?


The trigger to use Counterspell is:     1 reaction, which you take when you see a creature within 60 feet of you casting a spell   But what if the enemy is not using a spell but a magic ability? Should I allow my players to spend the magic space trying to counter the "magic"?


Is the genderless pronoun "they" appropriate and grammatical for a non-binary gender?

I recently had somebody tell me that a mutual friend of ours who is  prefers that people refer to him/her using the gender-indefinite pronoun they.   In some cases, this almost seems okay:   Kris left their umbrella at our house.  On the other hand, if Kris is sitting right next to you, it feels very odd to say       They (meaning just Kris) would like more cake.   Or even odder,      Kris would like some more cake, can you please pass it to they/them?"   Are these usages grammatically correct? Are they in the process of becoming grammatically correct? Are there more correct alternatives?


How to start Whatsapp Web on Ubuntu with Whatsapp installed on bluestacks on another computer?

I have recently installed bluestacks on a Windows 7 computer which isn't my normal one and I can't use it often and it's kind of annoying because I don't really own it.  I installed Whatsapp on that computer.  Since my normal computer runs Ubuntu I want to run Whatsapp or at least Whatsapp Web on this one.  I tried to scan an image with Whatsapp just on the Windows computers screen just to test whether this could work - the screen stays black.  Can I run Whatsapp on my own computer? If so, how do I make this happen?


Is "she don't" sometimes considered correct form?

Recently I was exposed to a lot of uses of "She don't + infinitive" ( + don't), instead of "she doesn't + infinitive" ( + doesn't). I'm not sure if it is a mistake or just accepted usage sometimes.   I found it in a very famous songs such as:   "" by Bon Jovi   Also in  (in 3:04)     But she don't know you like I know you Slim, no one does   She don't know what it was like for people like us growin' up, you gotta call me man   I'll be the biggest fan you'll ever lose   Sincerely yours, Stan, P.S. we should be together too   You can find a lot more by searching in you tube "he don't" or "she don't".


How to bulk re-index the whole site for core search?

I have a website that has about 100,000 nodes. In the core search page (admin/config/search/settings) it shows that:  There are 80801 items left to index.  It index 100 (or at most 500) nodes per cron run but it's useless. I want to bulk index the whole site (all nodes) for core search. How can I do that? The  and  modules are created for this but there are only a few users use these modules and I couldn't be sure to use them. And also there is a module called  for modifying the cron per job but it's still useless for me because there are thousands of nodes to index. (Note: I want to do this for core search not for other search solutions).


Using pdflatex, the command  $e^{a\overbrace{+b+c}}$   results in a bigger size font of the part +b+c under the brace. If I do:  $e^{a\overbrace{\scriptstyle +b+c}}$   the size of +b+c is fixed but the size of the brace is still wrong: the brace has the same size than before but, since the interior font is now smaller, white spaces appear.  Can we fix this?  NOTE: This question can be considered a duplicated of . However, the solutions in that question do not tackle the brace size problem. I don't have enough repuation to add this as a comment there and I don't think it is a good idea to add an answer that is rather a question.  NOTE2: Using mathtools does not change the problem.


Let $X_{1}, X_{2}, \ldots$ be exponential random variables with parameter $1 .$ Let $N$ be a geometric random variable with parameter $p$. Prove that $S_N = \sum_{i=1}^{N} X_{i}$ is exponentially distributed with parameter $p$. The sum of n exponential random variables with parameter $β$ is a $gamma (n, β)$ random variable, therefore $f_{S_N}(s) = \frac{1}{(N-1)!}s^{N-1}e^{-s}$ and it should be equal to $pe^{-ps}$. I just don't see how this can be possible. I feel like I have to apply Poisson process with rate 1 as $X_i$'s are interarrival times and $f_{S_N}(s) = P_{N-1}(s)$. Any hints?


How do I dynamically iterate through a subquery

This is the server-side code for a lightning component. Normally I would return the last line, but its commented out here to test using anon execution  I think I am calling the parent Id in the loop and not the child Id.  How can I get the child Id returned from the query dynamically?  // I will pass in the sObj and rID (record ID).  Specifying here to test. String[] sObj = new String[]{'Test__c'}; String[] rID = new String[]{'a0cr0000000LhhmAAC'}; // Array to pass back to return statement Set<Id> docIDs = new Set<Id>(); // Make the describe call Schema.DescribeSobjectResult[] results = Schema.describeSObjects(sObj); // Loop through the describe for(Schema.DescribeSobjectResult res : results) {     // Holds generated queries     List<String> subqueries = new List<String>();     String query ='';     // Get child relationships     Schema.ChildRelationship[] rels = res.getChildRelationships();     if (rels.size() > 0) {         //System.debug(res.getName() + ' has ' + rels.size() + ' child relationships.');         integer i = 1;         for(Schema.ChildRelationship rel:rels){             if (rel.getChildSObject().getDescribe().fields.getMap().get('Name') != null) {         // I only care if the relationship is a custom object                 if(rel.getChildSObject().getDescribe().isCustom()) {             // Get relationship name and field                     SObjectType childType = rel.getChildSObject();                     SObjectField lookupField = rel.getField();             // build the query or subquery                     subqueries.add('(SELECT Id FROM ' + rel.getRelationshipName() + ')');                     query = 'SELECT ' + String.join(subQueries, ',') + ' FROM '+ sObj[0] + ' where Id = \'' + rId[0] + '\'' ;             // Run the query with subqueries                     List<SObject> ids = Database.query(query);                     System.debug('Size: ' + ids.size() + ' - ' + query);             // I think this is where its wrong, try to loop through the query                     for(SObject idList:ids){             // only returns the parent id                         System.debug(idList.Id);             // only queries the parent id.  I think I am using the wrong field for id.  I need the id returned from the children                         List<ContentDocumentLink> cdl = [select id,contentdocumentid,contentdocument.Title from contentdocumentlink where linkedentityid = :idList.Id];                         for(ContentDocumentLink cdLink:cdl) {                             docIDs.add (cdLink.ContentDocumentID);                         }                 // The following 4 lines would be removed, and I would use the return statement at the end.  Leaving it here for testing                                 List<ContentDocument> q2ids = [Select id, title,fileextension from contentdocument where id in :docIDs];                                 for(ContentDocument cdLink2:q2ids) {                                     System.debug(cdLink2.Title);                                 }                     }                     i++;                 }             }          }     } } // Would normally use this line instead of the 4 above //return [Select id, title,fileextension from contentdocument where id IN :docIDs];


Calculate the limit of $\frac{1}{n+1} + \frac{1}{n+2} + ... + \frac{1}{2n}$

I'm stucked at calculation this limit. Using $Z_n =\sum\limits_{n=1}^{\infty} \frac{1}{n}$ I could rewrite my series as $Z_{2n} - Z_n$ but I couldn't go any further since harmonic series diverges and I wasn't able to calculate the sum.


This is a pretty vague question so please bear with me. I can add further information if required; just let me know in the comments. So here is the problem that I want to solve.  There is a system which gives certain voltage output which is the error in a system. It is a sinusoidal wave the peak to peak value of which is my error voltage. I have to take that error voltage and then give a voltage signal to an electronically controlled attenuator which then attenuates my system and changes the error voltage. Obviously I have to minimize the attenuator voltage. But here are the problematic parts:   There is an error null point of voltage which, when given to the attenuator, will nullify the error that null point is not known. The circuit has to find out that null point and keep the attenuator voltage there. The error null point may change change during the operation of the system due to different things. That may create some problems too.   Can someone help me design an electronic systems (maybe using op-amps?) to solve this problem?  Edit: We have a microcontroller-based system for this already. It uses the ADC of the controller and a DAC to give the voltage to the attenuator. But I just thought maybe there are simpler ways to do this.


How to show \listoffigures and \listoftables on consecutive pages?

Is it possible to put the list of figures and tables onto consecutive pages? The default configuration inserts a white page between both lists.  \listoffigures \listoftables   I have found  to put the list of figures and tables onto one page, but what I'd like is to clear the page after the list of figures.


How do I show the table names that exist in a Java SQLite3 database?

In the spirit of test-driven design I want to test whether the tables get properly created in my SQLite3 database. For that purpose I want to list the table names via an SQL query.   I created the tables with:  public static void setupTables(){     try(Statement stmt = con.createStatement()) {         String sql_student = ("CREATE TABLE IF NOT EXISTS " + STUDENT_TABLE + "(\n "                 + ID + " integer PRIMARY KEY,\n "                 + FIRSTNAME + " text,\n "                 + LASTNAME + " text\n"                 + ");");         String sql_teacher = ("CREATE TABLE IF NOT EXISTS " + TEACHER_TABLE + "(\n "                 + ID + " integer PRIMARY KEY,\n "                 + FIRSTNAME + " text,\n "                 + LASTNAME + " text\n"                 + ");");          stmt.execute(sql_student);         stmt.execute(sql_teacher);          stmt.close();      }catch(Exception e){         e.printStackTrace();     } }   What's the query I need for my test? Do I need to be concerned about order, or does the order in which the tables get created gurantee that they will always stored in the same order?


While trying to take screenshot for this  Achievements header is little overflow outside only in FF and working perfectly in IE10 and latest chrome browser. Managed to take 2 SS,      One more person @Richard Tingle is also having this problem, check his screenshot in this


What do I do with a 1 11/16" gap when installing a new pre-hung door?

I am replacing a door with a pre-hung door including the jamb. The old door was 29 11/16" wide. The new pre-hung door is 28".  Is this too big of a gap?  Should I make it plumb on one side and make up the difference on the other side? Other threads suggest making up space on the handle side, but this is more space than than what other people were asking about. The trim is 2 1/2" so the gap would be covered.


Equivalence Relation with dividing x and y integers

Define $x\sim y$ means 5 divides $(x - y)$ for $x$ and $y$ integers. Show that is an equivalence relation.  Equivalence relation means it satisfies reflexity, symmetry, and transitivity.  reflexive: $x\sim x$ means 5 divides $x$  symmetry: $x \sim y \rightarrow y\sim x$ means 5 divides $x - y$ and 5 divides $y - x$: $$5/(x - y) = 5/(y - x)$$ so symmetry is satisfied.  I am not sure if I am right here and I am lost on how to prove it is transitive any suggestions would be greatly appreciated


Where and how did magical genes in Harry Potter originate?

Did magical genes result from a slight change in the Human DNA? If so, who was(were) the first wizards? If they were pureblood magical wizards, how are the wizards today still pureblood, assuming that they may have bred with muggles?  Or was magic a sentient form that to earth from the heavens (other planets, species from wherever in the universe) and fuse with themselves with humans to create magical genes?  Did the magical gene distribute itself evenly among earth's population?


Can I claim to have completed my degree on my résumé, prior to convocating and receiving the physical diploma?

I just received my (passing) grades for my last remaining courses for my BSc. I’ve completed all my requirements, but the next convocation ceremonies don’t take place until Summer 2018. Likewise, I don’t think I will receive my diploma (the physical, official certificate) until then. Usually when a résumé says “degree expected in ____”, it reads along the lines of: “I’m not done yet, but if things pan out, I’ll hopefully be done by then“.  This is not my case, so in my résumé, how can I communicate across that I expect to receive my diploma in Summer 2018 as a matter of certainty?  Am I justified to use the term graduated? If so, should I say I graduated December 2017 (when I finished my requirements) or Summer 2018 (when convocation occurs)?


How to model a continuous variable lying between [0,1]

I have a set of data in which the dependent variable Y is a continuous random variable in the interval [0,1] (i.e. it can take the value 0 and 1). This is an insurance dataset so the Y has many 0 (about 96% of the number of observation). I would like to find a model for Y in which I can run a regression to find the relationship between Y and other predictors (like Age, Sex, Profession,...) but can't not find any proper type of regression that describes closely the variable Y. Could you please give my some suggestion ? I would like to thank you very much for your help!


Escaping arrays using mysqli escape string

I need to escape array's, I am using array_map with mysqli_real_escape_string.  I have multiple arrays like  $_post['countries']; $_post['categories']; . .   How do I perform escaping on these arrays  I am doing this way   $countries=array_map('mysqli_real_escape_string', $_POST['countries']); $categories=array_map('mysqli_real_escape_string', $_POST['categories']); . .   but it shows me error as Warning: mysqli_real_escape_string() expects exactly 2 parameters, 1 given in  also doing  $categories=mysqli_real_escape_string($connection, $_POST['categories']);    gives error as   Warning: mysqli_real_escape_string() expects parameter 2 to be string, array given in   Please see and suggest a way or another better way to do this.  Thanks


How to find perpendicular vector to another vector?

How do I find a vector perpendicular to a vector like this: $$3\mathbf{i}+4\mathbf{j}-2\mathbf{k}?$$ Could anyone explain this to me, please?  I have a solution to this when I have $3\mathbf{i}+4\mathbf{j}$, but could not solve if I have $3$ components...  When I googled, I saw the direct solution but did not find a process or method to follow. Kindly let me know the way to do it. Thanks.


I installed ubuntu 12.04 using wubi. But there is no application named " uninstall-ubuntu ". Now how can I uninstall it ?


What is the difference between the dashed and solid attack bars?

I was flipping through my Pokemon list to see which kind of attacks they had, and I notice there was a small different between the attacks. Some attacks contained a dashed blue bar where as others contained a solid blue bar.   What is the difference and significance between the two?


I'm using Ubuntu 13.10 (with JDK 1.7.0_45).  I've downloaded and uncompressed Eclipse Kepler for Java EE Developers.  The software menus are messed up. I didn't notice similar problems in other software.  When I click any menu in Eclipse, the drop-down seems to be "cut". Sometimes the drop-down shows, but the options are invisible.  I tried Eclipse Indigo, but the same problem occurs.


Why use a dedicated light meter instead of the one built into the camera?

I know a few people who carry around a dedicated light meter unit (such as ) and use that to meter photos instead of using the meter built into their cameras (and these are relatively new mid-range DSLRs).  Is there any good reason why someone would do this?


Pearson correlation binary vs continuous

I keep seeing that we can't use Pearson correlation for binary variables but I don't understand why. If instead of a binary response, I have multiple (>2) categories, then it's obvious - we are unsure about the ranking. However, let's just say we a binary gender (0- female, 1 - male) response and then some continuous variable (e.g. height)  B = matrix(  c(0,0,0,0,0,0,1,1,1,1,1,1,150,165,160,157,170,155,168,169,172,180,190,176), nrow=12,ncol=2)     [,1] [,2]  [1,]    0  150  [2,]    0  165  [3,]    0  160  [4,]    0  157  [5,]    0  170  [6,]    0  155  [7,]    1  168  [8,]    1  169  [9,]    1  172 [10,]    1  180 [11,]    1  190 [12,]    1  176  cor(B[,1], B[,2])}  0.7564467   Pearson correlation yields me a strong positive correlation of 0.76 - it seems only logical as men are taller in this sample. So why can't we use Pearson for variable preselection?


I am having problems solving two-variable mod equations.  How would one solve this?  $$ \left\{\begin{aligned} x + 3y &\equiv 1 \pmod{11} \\ 2x + y &\equiv 7 \pmod{11} \end{aligned}\right. $$


Mapping an entire network drive, not a folder

I click on the 'Map network drive' button on my server's 'Computer'.  There is a line asking for the 'folder' or essentially the network drive location.  I have another server running on the IP 10.132.2.98.  I can map a network drive to the address '\10.132.2.98\myfolder', but I get an error when I try mapping the drive to '\10.132.2.98'.  Is there a way where I can map my entire hard drive on the second server?


Find all $n,k \in \Bbb N^+$ such that $(n-1)!=n^k-1$  Using $n^k-1=(n-1)(1+n^2+...+n^{k-1})$ and cancelling $(n-1)$ in each side, we get that $$(n-2)!|1+n^2+...+n^{k-1}$$ So, let's suppose $n$ is an even number, in $(1+n^2+...+n^{k-1})$ we have $k$ terms, where $k-1$ are even ($n^i$ for $i>0$) and one is odd ($1$), so we have that $1+n^2+...+n^{k-1}$ is odd. Also, if $n$ is even, then $n-2$ has the same parity so n-2 is even; therefore, if $n-2>0$ then $(n-2)!$ is even and that is a contradiction. So with this, when n is an even number, the only solution is $n=2, k=1$ Now, in every other solution, $n$ is odd.  Let's suppose $k=1$. we have $(n-2)!=1$ (for $n, n-2$ odd) and it follows $n=3, k=1$.    Using this, if $n$ is odd, then $n^x$ is odd too, so it follows that we have $k$ odd terms, so if $k$ is even, then $(1+n^2+...+n^{k-1})$ is even, since every pair of terms sums an even number. From $n=4$ onwards, $(n-2)!$ is even so k has to be even too.   Let's suppose $k=2$. Then $$(n-2)!|n^2+1$$ $n=5$ works and let's prove is the only solution. Supose there is a $n=5+m$ for $m>0$. So: $$(m+3)!|m+6$$ And it's not hard to prove that $(m+3)!>m+6$ if $m$ is not $0$  So I got stuck here, I could only find these 3 solutions, and I don't know how to prove that there aren't more, since, for more bigger values it seems that $(n-2)!$ is greater if $k<n-1$. Would appreciate any help on the proof, or hints. thanks.


What is the most efficient way to concatenate strings in SQL Server?

I have this code:  DECLARE @MyTable AS TABLE (    [Month] INT,    Salary INT );  INSERT INTO @MyTable VALUES (1,2000), (1,3100);  SELECT [Month], Salary FROM @MyTable;   Output:    I want to concat the Salary (grouping by month) so that it will be NVARCHAR like this: '2000,3100'  How would I do this efficiently?


Let $p$ be prime and $n = p^2$. Show that the polynomial $1+px$ has a multiplicative inverse in $\mathbb{Z}_n[x]$. Is this polynomial invertible if $n = p^k$ for arbitrary $k>0$?


how to install ubuntu on a computer without using a monitor?

I have a computer but with no available screen, how can I install Ubuntu server on it using a laptop I have, I can't format the hard drive in another computer and buying a new monitor is not an option for me can you guys tell how can I do that?     The computer is pentium 4; 80 GB HDD; 800 MB ram; with external wifi adapter.   I think using ssh or network boot or something like that would be the way to do it, I'm not sure.


Can Boon of Luck be recharged on a long rest?

I was looking at the boons page in the DMG and the Boon of Luck says     You can add a d10 roll to any ability check, attack roll,   or saving throw you make. Once you use this boon, you   can't use it again until you finish a short rest.   Even though it doesn't say you can use it again after a long rest, does it recharge after a long rest and a short rest or only a short rest?


How long is a question unable to be closed after the grace period expires?

I'd like to close-vote  as off-site resource request, but can't, due to a bounty. The bounty has expired, and the grace period has ended, so it seems reasonable that the question can be closed voted.    How long until it can be closed, after the grace period ends? Is there a reason why this period (post-grace lock on cv'ing) exists?   I can't find any reference to this in the  FAQ.


I am taking an undergraduate course in computer science an is in the first year of my college. I like mathematics and am willing to learn Linear Algebra first and then move on to Abstract Algebra and further into Topology ,Computational Geometry and other parts like Number Theory,Probability and Discrete Mathematics.  Now my friend in an undergraduate course in Mathematics told me that their professor has recommended "Finite Dimensional vector Spaces" by Halmos for the first course in Algebra. I found that book to be a bit tough. So I coupled it with Sheldon Axler's "Linear Algebra done Right" looking for more basic explanations or background knowledge. But my friend says that he has heard that Axler's book is not good and lacks in providing proper concept.   Which book is going to be good for backing up Halmos. It is not that I am unable to understand. But I feel that I need more background knowledge. Which book should I read to get that background knowledge. Am I doing things wrong ? Should I restart learning Linear Algebra from the beginning ?   I am a pretty much beginner in abstract mathematics. Please help.


Can we apply De Morgan law on arbitrary Unions and Intersections, or it is only restricted to finite ones?


How to find eigenvectors and eigenvalues for a matrix whose entry a_ij is given by ij

Could someone please help me with this question: Let A be the n×n matrix whose elements are given by a_ij = ij. Find its eigenvalues and its eigenvectors. The only way I can think of is taking the determinant of A-labda*I, but this seems like very tedious work. Then I thought I should first apply Gauss-Jordan elimination, but I'm really stuck on how to do that here. Any help would be very much appreciated! Ps. Is there a name for this kind of matrix? If there is, that would be helpful for googling!


Truncate Float value up to two decimal point in java

DecimalFormat hisFormat = new DecimalFormat("########.##"); hisFormat.setRoundingMode(RoundingMode.DOWN);  Float x=12345678.12345f; System.out.println("Float Value " + hisFormat.format(x));   Above code print "Float Value" as 12345678 I need 12345678.12  How can I get my result? Please let me know.


US citizen traveling with Peruvian passport

I'm an American citizen. I was born in the US, however I came to visit Ecuador on an emergency basis using my Peruvian passport. I lost my US passport and had no time to get one before coming to Ecuador. Can I fly back to the US with my Peruvian passport only or will I be denied entry? I have my US drivers license, and SS card on me. I don't have a visa since I am a citizen and resident in the US.


Warning in query plan "Cardinality Estimate"

create table T(ID int identity primary key) insert into T default values insert into T default values  go  select cast(ID as varchar(10)) as ID from T where ID = 1   The query above has a warning in the query plan.  <Warnings>   <PlanAffectingConvert ConvertIssue="Cardinality Estimate" Expression="CONVERT(varchar(10),[xx].[dbo].[T].[ID],0)" /> </Warnings>   Why does it have the warning?  How could a cast in the field list affect the cardinality estimate?


How to figure out why I'm banned, and why am I getting banned

So, just today I was browsing Stack Overflow's questions, fixing grammar, answering posts, then I get a question in my head, when I got to click on the "Ask a Question" tab, it says "We are no longer accepting questions form this account"...  Non of my questions have any downvotes, and I have accepted a best answer for all of them.  Why would I be getting banned from asking questions all the sudden?  This all the sudden happened today.  I don't recall doing anything that made me not able to ask questions anymore.


I am working through some practice problems and I have this one which is stumping me:  Take $f$ and entire function such that $f(z) = f(z+1)=f(z+\sqrt{2})$, then it is constant.  I was thinking, given the function is entire, then it has a Taylor series expansion about the origin, with an infinite radius of convergence:  $$f(z) = \sum_{n=0}^{\infty} \frac{f^{(n)}(0)}{n!}z^n=\sum_{n=0}^{\infty} \frac{f^{(n)}(0)}{n!}(z+1)^n=\sum_{n=0}^{\infty} \frac{f^{(n)}(0)}{n!}(z+\sqrt{2})^n$$  Which we can also write:  $$\sum_{n=0}^{\infty} \frac{f^{(n)}(0)}{n!}z^n = \sum_{n=0}^{\infty} \frac{f^{(n)}(0)}{n!}\sum_{k=0}^{n}{n\choose k}z^k = \sum_{n=0}^{\infty} \frac{f^{(n)}(0)}{n!}\sum_{k=0}^{n}{n\choose k}z^k\sqrt{2}^{n-k}$$  But I am not quite sure this is the correct place to go. Any ideas as to how I can move forward on this problem?  Thank you!


How to drop the https from urls in bibliography using biblatex and hyperref

I am using biblatex to generate a bibliography and using hyperref for clickable links. I want to set a reference to a website. Let's say Ansys' one using the @online class. So my .bib file would contain something like this:  @online{ansysTag,     title = {ANSYS Studio},     url = {https://ansys.com/},     urldate = {2020-04-01} }   I would like to get rid of the 'https' in the printed bibliography as it looks unaesthetic and useless. Similarly to . But if I get rid of the https in the url field, the link is not clickable anymore. I tried replacing it by \href{https://ansys.com/}{ansys.com} but this would not work either.  Is there a simpler solution ? Thanks.


How to float a variable declared by an equation to two decimal places in java

How to I make the answer display in two decimal places?  runningCalories  = 0.0175 * RUNNING_METS * weight * TIME_RUNNING; System.out.println(name + " burned an estimated " + runningCalories + " calories running.");


Switch statement fall-through...should it be allowed?

For as long as I can remember I have avoided using switch statement fall-through. Actually, I can't remember it ever entering my consciousness as a possible way to do things as it was drilled into my head early on that it was nothing more than a bug in the switch statement. However, today I ran across some code that uses it by design, which got me immediately wondering what everyone in the community thinks about switch statement fall-through. Is it something that a programming language should explicitly not allow (like C# does, though it supplies a workaround) or is it a feature of any language that is powerful enough to leave in the programmer's hands? Edit: I wasn't specific enough to what I meant by fall-through. I use this type a lot:     switch(m_loadAnimSubCt){         case 0:         case 1:             // Do something             break;         case 2:         case 3:         case 4:             // Do something             break;    }  However, I'm concerned about something like this.    switch(m_loadAnimSubCt){         case 0:         case 1:             // Do something, but fall through to the other cases             // after doing it.          case 2:         case 3:         case 4:             // Do something else.             break;    }  This way whenever the case is 0, 1 it will do everything in the switch statement. I've seen this by design and I just don't know if I agree that switch statements should be used this way. I think the first code example is very useful and safe. The second seems kind of dangerous.


What is the meaning of these two expressions:  the pitch was now coming across the plate  I was staring at my chance to knock the ball out of the park   These two phrases was taken from the text below:  With all the lessons I had learned from my trial-and-error days in the 1980s, the pitch was now coming across the plate, and I was staring at my chance to knock the ball out of the park.


Logarithmic loss vs Brier score vs AUC score

I have a dataset with two classes of elements. I also have two methods which assign (complementary) probabilities to each element in the dataset of belonging to either class.  Given that I work with probabilities (instead of hard 0,1 classification values), I was pointed to  as a way to asses which method performs better. The two most used rules appear to be:    (Log loss, logistic loss, cross-entropy loss)  (Brier score)   with Log loss apparently being the standard approach (is it?). I also found scikit-learn's  , an implementation of the:    (AUC, ROC-AUC)   which appears to do pretty much the same thing.  My question is: is either one of these inherently "better" than the other in some form? I also could just use all three. Is this advisable?


MacBook Pro black screens and shuts off after a few minutes' use

I have a MacBook Pro 15" (mid 2014, running Sierra). Recently, it has started black screening and shutting off shortly after, after a few minutes' use—let's say 3 to 10 minutes. The screen will go black but the LCD backlight will remain on for about 5 seconds, then the laptop will completely shut off.  I have reset PRAM and the SMC. Things I have determined:   The built-in hardware test passes Problem is not tied to my user account (occurs when I'm logged in to another freshly created user) Problem is not tied to my OS installation (I wiped and re-installed) Problem does not manifest itself in Safe Mode or when booted into Windows 10. (Also didn't manifest during OS X re-installation.) Problem does not seem to be overheating: I can game with no issues on Windows, graphics performance and fans are fine.   This behaves like a classic overheating problem, but I'm stumped due to some of the weirdness of it not being an issue in safe mode or Win 10. Any thoughts?


Every night I get hundreds, sometimes thousands, of failed ssh logins on my RedHat 4 server. For firewall reasons from remote sites, I need to run on the standard port. Is there anything I should be doing to block this. I notice that many come from the same IP address. Shouldn't it be stopping those after a while?


I've been learning how to use Blender, and I've come across a tutorial which talks about UV Unwrapping, but it isn't the same version of Blender that mine is so I have no idea what to do now. My version is 2.79  The editor looks like this:   But when I render it (with F12) it just shows this:   How do I make the render show the texture?


I have set a post to private on a WordPress multisite so users should be redirected to a 404 page. The permalink of this post is http://local.website.com/en/event.  Now WordPress seems to redirect requests to event to event-30-01-2016. WordPress seems to focus on the lower number after the event string. Example: it will prioritise event-29-05-2015 over event-30-05-2015.  I want to keep the URLs for posts like event-* but I want event to redirect to 404 since I kind of disabled the page.  My settings on /wp-admin/options-permalink.php are set to Post name.  I don't have any special rewriteRules in .htaccess for events.  This is my .htaccess:  # BEGIN WordPress RewriteEngine on RewriteBase / RewriteRule ^index\.php$ - [L]  # add a trailing slash to /wp-admin RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]  RewriteCond %{REQUEST_FILENAME} -f [OR] RewriteCond %{REQUEST_FILENAME} -d RewriteRule ^ - [L] RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L] RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L] RewriteRule . index.php [L] # END WordPress   Is there maybe a hook that I could use in order to disable this kind of redirection?


Keeping a linux process running after I logout

I'm connecting to a Linux machine through SSH, and I'm trying to run a heavy bash script that makes filesystem operations. It's expected to keep running for hours, but I cannot leave the SSH session open because of internet connections issues I have.  I doubt that running the script with the background operator, the ampersand (&), will do the trick, because I tried it and later found that process was not completed. How can I logout and keep the process running?


I have a question about the visa needed to transit in Korea.  I'm an Indonesian passport holder and am traveling to the US. On the way back I have a transit of 24 hours at Incheon. If I want to go out and stay in Seoul, do I have to apply for a visa? Or can I get a transit visa on arrival?


I can't undestand why $ \{x \in X : f(x) > g(x) \} = \bigcup_{r \in \mathbb{Q}}{\{x\in X : f(x) > r\}\cap\{x\in X:g(x) < r\}} $

I'm trying to understand this equality:  $$ \{x \in X : f(x) > g(x) \} = \bigcup_{r \in \mathbb{Q}}{\{x\in X : f(x) > r\}\cap\{x\in X:g(x) < r\}} $$  $X$ is a measurable space and $f,$ $g$ are measurable functions. As, $f$ is measurable, then $\{x\in X : f(x) > r\}$ is measurable. The same goes for $g.$ The intersection between these sets would be measurable, and the countable union, $\bigcup_{r \in \mathbb{Q}}{\{x\in X : f(x) > r\}\cap\{x\in X:g(x) < r\}}$ would then be measurable.   I have been trying to visualize what this union means, employing some examples (not numeric, but general shapes of graphs).   For example, if $f(x) = c, c\in \mathbb{R}$ and, $g(x) = d, d\in \mathbb{R}$, and $c \neq d,$ $\bigcup_{r \in \mathbb{Q}}{\{x\in X : f(x) > r\}\cap\{x\in X:g(x) < r\}} = \mathbb{R}.$   Clearly, the domain where the functions are defined, should be equal, or have at least some intersecting region, because in other case, the union is empty.   It is possible to create graphs, for which the union is empty, even though the functions are defined in a same interval. And in lots of cases, there are one ore several intervals of intersection.   But I still don't have a clue as to why the equality holds. This would show that $  \{x \in X : f(x) > g(x) \}$ is measurable.


If $\sum_\limits{n\in\mathbb{N}}{b_n}$ is divergent, then so is $\sum_\limits{n\in\mathbb{N}}{\dfrac{b_n}{1+b_n}}$?

I want to prove the following:   Suppose $\sum_\limits{n\in\mathbb{N}}{b_n}$ is divergent. Then $\sum_\limits{n\in\mathbb{N}}{\dfrac{b_n}{1+b_n}}$ is divergent.  I think you have to prove by contradiction and by using Cauchy's criterion. But how to start with that? Or is it possible to use another well-known criterion?


I am taking an online class on algorithms and I had the following quiz. I got it wrong and am trying to understand the reason for the answer.  Which of the following is O(n^3)? a) 11n + 151 gn + 100 b) 1/3 n^2 c) 25000 n^3 d) All of the above.  The correct answer is (d) all of the above. The reason is that Big-O notation provides only the upper bound on the growth rate of function as n gets large. I am not sure why the answer is not (c). For example, the upper bound on (b) is less than n^3.


How can I set text to be multi-line on a multirow table? I'm referring to row 5 column 1. Thank you    \documentclass{report} \usepackage[margin=0.5in]{geometry} \geometry{margin=1in} \usepackage{graphicx} \usepackage[table,xcdraw]{xcolor} \usepackage{tabularx} \usepackage{multirow} \usepackage{ragged2e} \newcolumntype{C}{>{\centering\arraybackslash}X}  \begin{document}  \begin{table}[h!] \centering \small \setlength\tabcolsep{3pt} \renewcommand\tabularxcolumn[1]{m{#1}} \begin{tabularx}{\linewidth}{     |>{\hsize=1.0\hsize}C|% 10% of 4\hsize      >{\hsize=1.0\hsize}C|% 30% of 4\hsize     >{\hsize=1.0\hsize}C|% 30% of 4\hsize         % sum=4.0\hsize for 4 columns   } \hline  \textbf{Instituição} & \textbf{Estágio} & \textbf{Duração}\\ \hline  \multirow{4}{*}{Hospital de Origem} & Radiologia convencional e estudos contrastados & 6 meses \\  & Ecografia Geral e Ecografia Ginecológica & 6 meses \\  & Eco-Doppler & 1 mês \\  & Tomografia Computorizada & 6 meses \\ \hline  \multirow{3}{*}{Hospital de Origem depois} & Radiologia convencional e estudos contrastados & 3 meses \\  & Neurorradiologia & 3 meses \\  & Ressonância Magnética & 3 meses (a tempo parcial) \\ \hline  CHospital de Origem com texto grande (muito grande) & Eco-Doppler & 2 meses \\ \hline  \multirow{4}{*}{Hospital de Origem enorme e acontece isto porque} & Radiologia Mamária & 3 meses \\  & Medicina Nuclear e Densitometria Óssea & 1 mês \\  & Radiologia do Pescoço &  0\\  & Radiologia de intervenção &  0\\ \hline  \end{tabularx} \caption{Distribuição do Internato de Formação Específica} \label{tab:exemplo} \end{table}  \end{document}


Same integration with 2 different answers?

$$\int x(x^2+2)^4\,dx $$  When we do this integration with u substitution we get $$\frac{(x^2+2)^5}{10}$$ as $u=x^2+2$  $du=2x\,dx$ $$\therefore \int (u+2)^4\,du = \frac{(x^2+2)^5}{10} + C$$   Although when we expand the fraction and then integrate the answer we get is different:  $x(x^2+2)^4=x^9+8x^7+24x^5+32x^3+16x$ $$\int x^9+8x^7+24x^5+32x^3+16x \,dx$$  we get  $$\frac {x^{10}}{10} +x^8+4x^6+8x^4+8x^2 + C$$  For a better idea of the questions, let's say the questions asks us to find the value of C when y(0)=1  Now,  $x=0$  $$\frac {0^{10}}{10} + 0^8 + 4(0)^6 + 8(0)^4 + 8(0)^2 + C = 1$$ $$\therefore C= 1$$ AND $$\frac {(0+2)^5}{10} + C= 1$$ $$\therefore \frac {32}{10} + C = 1$$ $$\therefore C = 1 - 3.2 = -2.2$$


Quotient of a PID by a prime ideal is a PID too.

I am trying to prove that if $R$ is a PID and $P$ is a prime ideal of $R$ then $R/P$ is also a PID. This is question 8.2.3 from Dummit & Foote.  My thoughts and what I know : $P$ is also maximal. $R/P$ is hence a field. Also is an integral domain due $P$ being prime. $P$ is generated by by some element of $R$, say $a$, written as $P=(a)$. My conjecture is that an ideal $I$ of $R/P$ is generated by the coset $a+P$, ie. $I=(a+P)$.   I am having some trouble understanding that the set $I$ is equal to a set generated by a coset. I'm not sure how to show the inclusions to show that those two sets are the same. Any help is appreciated. Thanks for your time.


How to include maven dependencies in a jar file?

I have an eclipse Luna project with a bunch of maven dependencies defined in a pom.xml  Everything works fine in eclipse. But now I need to include all of those dependencies in an exportable jar file (so that I can ship them to workers in Apache Spark).  I keep fiddling with the export settings, but I don't see any way to export them into the jar file.     I find some answers explaining how to configure maven to package its dependencies. Is that my only option, or is there some way to do this in eclipse?


Make Bash autocomplete guess the closest approximation

I have a somewhat uncomfortable keyboard on my laptop, resulting in that I sometimes misspell things in Bash and when pressing Tab for an auto-completion nothing happens.   Is it possible to have Bash guess what I meant to type, by for example when wanting to change directory to Documents and then mistyping cd ocum[TAB], given no other folder beginning with "ocum" is present, Bash interprets it as cd Documents/ since it is the closest possible action to do?   Or is this idea terribly complicated to achieve?


Internal keyboard and trackpad stop working after plugging in USB device

I got a new MacBook Pro with OS X Mavericks. When connecting my phone via USB, the internal keyboard and the trackpad immediately stop working -- not always but in most cases. The bluetooth mouse and an external USB keyboard are not affected. Everything else works also fine. The power button of the internal keyboard still works. Reboot helps. Any ideas?


OpenLayers does not appear in the QGIS plugin menu

I have installed the , which features external map layers in QGIS. Quoting the official page:     OpenStreetMap, Google Maps, Bing Maps layers and more   In QGIS, it seems that the plugin is well installed:    However, no new items were added to the plugin menu:    Any idea how to start the plugin? I have tried restarting QGIS and reinstalling the plugin several times, with no success.


Here's the problem I'm working on: Let k be an algebraically-closed field, and let $X \subseteq \mathbb{A}^2$ be a closed, irreducible set. Show that either:  $X = Z(0)$, i.e. $X = \mathbb{A}^2$ $X = Z(f)$ for some irreducible $f \in k[x,y]$ $X = Z(x-a,y-b)$, i.e. $X$ is a single point  Deduce dim$(\mathbb{A}^2) = 2$. (Hint: Show that the common zero locus of two polynomials $f,g ∈ k[x,y]$ without common factor is finite.) Here's what I have so far: we know every irreducible closed subset of $\mathbb{A}^2$ corresponds to a prime ideal in $k[x,y]$. This makes the first couple cases simple: If $X$ corresponds to the zero ideal $(0)$, we get case 1. If $X$ corresponds to a principal prime ideal we get case 2, because $k[x,y]$ is a UFD and in a UFD every non-zero element $f$ is irreducible iff $(f)$ is a prime ideal. The issue I'm having is I don't know how to show case 3. By Hilbert's Nullstellensatz we know single points in $\mathbb{A}^2$ correspond to maximal ideals in $k[x,y]$, so it would suffice to show that any non-principal prime ideal in $k[x,y]$ must be maximal. I don't know how to prove the hint, or quite how to use it. I know any set of $n$ points in $\mathbb{A}^2$ will correspond to an intersection of $n$ maximal ideals in $k[x,y]$. But again I don't know what to do with this. Once I have the three cases done I believe I know how to show $\mathbb{A}^2$ has dimension 2. Thanks in advance.


Citation becomes disordered after using command "\listoffigures"

I'm writing my thesis in Overleaf. and I'm now trying to generate a content of figures using the command "\listoffigures", and now the content of figures is generated, but all citations become dosordered. :( \listoffigures \addcontentsline{toc}{chapter}{List of Figures} \clearpage  And when I delete the command "\listoffigures", they become again in the correct order (start from [1],[2],[3],[4]...). I also tried the command "\bibliographystyle{unsrt}" but it's not helping. \bibliographystyle{unsrt} \renewcommand\bibname{Reference} \bibliography{Reference}  The citations in the doc "Reference.bib" are generated by citaiv and copied to Overleaf. They are not in the order how I cited them, but I think it shouldn't be a problem. Doest anybody know why???


How does gedit detect the encoding of a text file?

How does gedit detect the encoding of a text file when opening it? I notice that gedit can always find the correct encoding when opening a text file of mine, while chardet can often fail to and emacs can sometimes fail too. Is it because I created the text files under gedit, and gedit might save some encoding information as metadata to the text files during their creation?  Can I run gedit in command line to detect encoding of a text file, just like chardet does? That will be convenient when I want to write shell commands for batch processing text files.   Thanks.


I'm trying to sort a list consisting of names and numbers, in this case a persons name and their bowling score. I want to sort the list alphabetically and numerically. I'm having a hard time figuring out how to sort the list numerically. The list looks like this: ['', 'Ann, 40', 'Jeff, 250', 'Zane, 20']. Is there anyway I can use the built in sort function for the second element in the list rather than the first?  #Here is the code l=['Ann, 40', 'Jeff, 250', 'Zane, 20']   l.sort(l[1]) for i in l:     print(i) #l.sort(l[1]) does not work   The end goal will be to display  Jeff, 250 Ann, 40 Zane, 20


Are there any spells or magic items that allow a user to bypass fire resistance?

A bit of a specific request I know, but for an upcoming battle my DM is throwing at us, I'll be using a magical weapon that deals fire damage and we know the creature has fire resistance. So I was wondering if there were any options to ignore the opponent's fire resistance. I know of the Elemental Bane spell already, but if there were any other spells that had this effect as well that would be helpful to know as well.


Print Solution seperately in exam document class

I want to print answers separately after the end of the the questions in exam document class. Guide me.   Which is/are the neighbouring countries of India? A. Nepal  B. USA  C. Thailand  D. China Who introduced mid-meal scheme in Tamil Nadu? A. Kamarajar  B. M.G.Ramachandran  C. C.N.Annadurai  D. Thandai Periyar   Solution: 1. (A, D) Hint: Thailand and USA are not neighbouing countries 2. (A) Hint: Kalvikanthiranda Kamarajar.


Let $k, m, n \in\mathbb Z^+$, where $k$ and $m$ are relatively prime. Prove that if $k|mn$ then $k|n$ .

I'm trying to complete this question but it has me a little stumped!   Let $k, m, n \in\mathbb Z^+$, where $k$ and $m$ are relatively prime. Prove that if $k|mn$ then $k|n$ ($k|mn$ implies that $k$ divides $mn$ and $k|n$ implies that $k$ divides $n$) .


Can a player make a persuasion roll on another player?

We ran into a recent issue in my group where one of the PCs attempted to persuade another. The character who was being persuaded mentioned something about how persuading another PC is not allowed. I, being unclear on the ruling, asked them to wait on a verdict until I had a clear answer, as neither could find any evidence that it was allowed or not.  Is this allowed? If so, how can I stop it from being escalated? Knowing the player, he will get mad about being persuaded, and will likely pull some sort of stunt along the lines of, "I'll make a persuasion check to make you give me X" over and over again to prove that it shouldn't be allowed. Is there a way to avoid this?


Rotate camera around object for animation

I would like to get the camera to slowly rotate around a object and keep facing it. I would to this with key frames but then the camera would travel in strait paths. How could I do this?


I am on a MacBook Air and using a guest account. I am trying to access a USB, but I can't

Ok, so here's the deal. I have a picture, from Google Images, that I am trying to put on a flashdrive or such so I can make it the profile picture to the account I am currently logged into. I have the latest OSX and everything is up to date. I am on a Safari only guest account. Whenever I try to download anthing to the computer directly, I only get a "Safari could not download the file “Just Another Day For Arceus.mp4” because there is not enough free disk space. Try deleting documents or downloading to another disk." This of course, was trying to download a video, not the said picture. That, and when I try to right click items, the usual white bar with several items does not appear. I can access the USB, however, when I go to Google's homepage and click "Change Image" and although I can access the files already on it, I cannot add any new files. Please help if you can, and let me know if I can do anything without logging into the Admin account. Also, I am not much of a tech person, so if you try to give me pathways, I won't know what to do with them, nor how to use them.  Thank you so much in advance,  Drena The Eliatrope


Should editing / adding tags bump the question to the front page?

I edited an older question and then people complained about bumping such an old question to the front page for a minor edit.  If such an edit is not worth bumping the question, I think this should not stop you from editing, but is a misfeature of the site to bump it to the front page. Either there should be a threshold when a questions is bumped (and maybe an age limit) or an option for the editor to prevent bumping.  Then questions can be improved without annoying somebody.  While there is a point in getting more reviews of edits, this prevents at least implicitly by discouraging them through complaining users drive by edits, where I for example cannot really help with the question, but correct some minor issues like wrong tags or spelling errors. I think nothing should prevent someone from improving a question or answer, but of course not everybody needs to see the question again just because some punctuation was changed.


Wouldn't it be nice if we have a command to end an environment in a generic way? Example:  \begin{itemize}    \item Apple    \item Banana \endenv       % replaces / is an alternative to, \end{itemize} or any other environments.   so that if I change my mind, I can just replace the first line with, for instance, \begin{enumerate}, without changing the closing part. This is also useful when one changes from normal to starred environment, etc.  This feature would serve as an alternative to the normal closing, which will still be available. And this hypothetical \endenv can be restricted to work only for 'normal' environment, and will not work for complex ones such as verbatim, frame, listings.  Should we have that \endenv? Is there already a package for this feature?  Edit:  To future visitors: from the accepted answer below one can see that this is not a very good idea. If one still demands the presumed convenience, this kind of thing should/can be delegated to the editor.


Getting what appear to be reopen audits in close vote queue

I just noticed this:    Really? A closed question is in the close vote queue? Not likely.  It seems that the action to take on these is to click leave open - which passes the audit. I got  before this and clicked close and failed the audit.  Could this be fixed? Please?


Carrying confidential corporate data into US on laptop/Drive/device - how to prevent data theft?

If I travel to the US and had privacy concerns (for instance may be I was afraid that a rogue customs official may steal said data) what is the current recommended best practice to avoid this?


Minimum of a function on an open interval

Suppose that f is continuous on $(a,b)$ and $\lim_{x\to a^+}  f(x) = \lim_{x\to b^-} f(x) = \infty$. Prove that $f$ has a minimum on all of $(a,b)$.  I was thinking of applying the extreme value theorem, but I realized that it applies only to closed intervals. So I was thinking of defining a closed interval that is in $(a,b)$, and using the definition of one sided limits to go about the problem, but I don't know how to proceed. Help please?


I did a hard-reset, wiped everything everywhere, reinstalled firmware and changed SD card. However, the phone still works extremely slowly, not as when it was bought. What can wear out in phone? Inner flash memory or something else?


How do I allow a non-default user to use serial device ttyUSB0?

I have an Ubuntu 11.10 system with 2 users:   The first was created during the installation The second instead was created after. It belongs to the sudoers group.   Now the problem is that when the second tries to use a device ttyUSB0 the following error is returned:  "Could not open serial port /dev/ttyUSB0"   I was able to fix it by using:  sudo chown :second_user /dev/ttyUSB0   However when I disconnect the device and reconnect it the problem comes back.  Is there a way to allow different users to access the devices? I suppose I have to add the user to a specific group. Currently the owner is root and the group is dialout. However I'm not sure about the group and I don't know how to add the user.  Thanks!


How do I round a double to the thirds place?

double1 = .05100000000003;  double2 = .05295;  How do I round a decimal to three places? Respectively, I'd like the output to do this 0.051 and 0.053. I tried Math.round(double1); but I got back 0.0. Any ideas would be greatly appreciated thanks.


Can I apply for a Schengen business visa from other country where I went for tourism?

If I am a citizen of country A and I went for tourism to country B. Means I am not there for long stay or have temporary residence, student or work purposes but short stay just for tourism. So can I apply a Schengen visa for business purposes from country B or I must apply from country A where I'm citizen?   Please don't duplicate my question with this question  I am not asking this.


Memory alignment and padding — difference between 32 and 64 bits

I would like to understand the results got with "gcc -m32" and "gcc -m64" compilation on the following small code:  #include <stdio.h> #include <stdlib.h>  int main() {  struct MixedData {  char Data1;  short Data2;  int Data3;  char Data4; };  struct X {  char c;  uint64_t x; };  printf("size of struct MixedData = %zu\n", sizeof(struct MixedData)); printf("size of struct X = %zu\n", sizeof(struct X)); printf("size of uint64_t = %zu\n", sizeof(uint64_t));  return 0; }   With "gcc -m32", the ouput is :  size of struct MixedData = 12 size of struct X = 12 size of uint64_t = 8   Is size of struct X equal to 12 because compiler sets the following padding?  struct X {  char c;     // 1 byte  char d[3];  // 3 bytes  uint64_t x; // 8 bytes };   If this is the case, what's the size of a single word with 32 bits compilation (4 bytes?)? If it is equal to 4 bytes, this would be consistent because 12 is a multiple of 4.  Now concerning the size of MixedData with "gcc -m32" compilation, I get "size of struct MixedData = 12". I don't understand this value because I saw that total size of a structure had to be a multiple of the biggest size attribute in this structure. For example, here into structure MixedData, the biggest attribute is int Data3 with sizeof(Data3) = 4 bytes; why don't we have rather the following padding:  struct MixedData {  char Data1;        // 1 byte  char Datatemp1[3]; // 3 bytes  short Data2;       // 2 bytes  short Data2temp;   // 2 bytes  int Data3;         // 4 bytes   char Data4;        // 1 byte  char Data4temp[3]  // 3 bytes };   So the total size of struct MixedData would be equal to 16 bytes and not 12 bytes like I get.  Can anyone see what's wrong about these 2 interpretations?  A similar issue is about "gcc -m64" compilation; the output is:  size of struct MixedData = 12 size of struct X = 16 size of uint64_t = 8   The size of struct X (16 bytes) seems to be consistent because I think that compiler in 64 bits mode sets the following padding:  struct X {  char c;     // 1 byte  char d[7];  // 7 bytes  uint64_t x; // 8 bytes };   But I don't understand the value of struct MixedData (12 bytes). Indeed, I don't know how compiler sets the padding in this case because 12 is not a multiple of memory word in 64 bits mode (supposing this one is equal to 8 bytes). Could you tell me the padding generated by "gcc -m64" in this last case (for struct MixedData) ?


Term for a trademarked word that is used as a synonym for the item it represents

Apologies in advance if this is a duplicate.  For instance, when I say, "I need a Kleenex" and by that I mean "I need a tissue regardless of the brand", is there a term for words like Kleenex in this context?  I could've sworn this word exists, and probably ends in -nym. For the life of me, I can neither recall it nor find it anywhere, including this forum where I did a search for things like synonym, hypernym, brand and trademark.  Other words like this include Band-Aid, Jacuzzi and Chapstick.  Here are some sample sentences:     In the UK, Biro is a _____ that can refer to any ballpoint pen.   or     The _____ windbreaker can mean a lightweight jacket of any brand.   or     (InE) "Bring me some Maggi from the store."      "Do you want Maggi noodles specifically, or did you use Maggi as   a _______?"   For the record, I would settle for any word or compound word that fits; it doesn't have to end in -nym. I would prefer a single-word answer.  This  by Business Insider lists more words like this, and says the process is called genericization, but doesn't state a term for such words.  PS - I do not care about the part of speech. For example, I think that the noun Google, when used as a verb, falls under this umbrella. But even if it doesn't, is there a term that covers the other examples I mentioned?  Read more at:


Error Analysis and Modes of Convergences

I have the following question regarding Modes of Convergence          Recall that the Taylor series of the function $f(x) = \ln(1+x)=\sum_{n=1}^{\infty}(-1)^{n-1}\frac{x^n}{n}$. Let $f_{N}(x)=\sum_{n=1}^{N}(-1)^{n-1}\frac{x^n}{n}$ be the partial sum. Determine whether $f_N$ converges pointwise, uniformly, or in the $L^2$ sense to $f$ on $-1\leq x\leq1$.      I am kinda sketchy on whether it converges pointwise - well in general actually - for $-1$ since $\ln(1+-1) = \ln(0)$ is undefined. If I disregard this, let's take a look at what we know. $\ln(x+1)$ = $\sum_{n=1}^{\infty}(-1)^{n-1}\frac{x^n}{n}$ converges on $|x|<1$ by the ratio test. The ends would be of concern, but $1$ is okay. Not so much $-1$. Anywho, this is what I have.  Pointwise Converges: Consider $f(x) = \sum_{n=1}^{\infty}(-1)^{n-1}\frac{x^n}{n}$ and its $N$th partial sum $f_{N}(x)=\sum_{n=1}^{N}(-1)^{n-1}\frac{x^n}{n}$. The infinite series converges pointwise to $f(x)$ on $-1\leq x \leq 1$ if   $ \begin{eqnarray}  | \sum_{n=1}^{\infty}(-1)^{n-1}\frac{x^n}{n}-\sum_{n=1}^{N}(-1)^{n-1}\frac{x^n}{n}|\\ |(x-\frac{x^2}{2}+\frac{x^3}{3}-\frac{x^4}{4}+\frac{x^5}{5}+...)-(x-\frac{x^2}{2}+\frac{x^3}{3}-\frac{x^4}{4}+\frac{x^5}{5}+...)|\\ |(x-x)+(-\frac{x^2}{2}+\frac{x^2}{2})+(\frac{x^3}{3}-\frac{x^3}{3})+(-\frac{x^4}{4}+\frac{x^4}{4})+(\frac{x^5}{5}-\frac{x^5}{5})+...| \longrightarrow 0\\ \end{eqnarray} $  as $N \rightarrow \infty$, for every $x\in[-1,1]$.  However, for some reasoning I am doubting it actually converges on the entire interval. I could just be over thinking it. The point is to show the error between $f(x)$ and $f_N(x)$ tends to zero as $N\rightarrow \infty$ for every $x$ on the interval and it seems to do just that.  Uniformly Convergence is similar; however, it focuses on uniform error between $f(x)$ and $S_N(x)$ tends to zero as $N\rightarrow \infty$. If want to conclude it also tends to zero. Same goes for $L^2$ sense.  Any suggestions? Thank you for your time and Thanks in advance for any feedback.


Why did Stack Overflow choose to launch a Portuguese site before any other language?

I already read Stack Overflow has released . So I would like to ask a question.  Why did Stack Overflow choose the Portuguese language over Chinese or other languages?


A word for one who is sacrificed or suffers so others need not

Although the word martyr somewhat applies, it includes a nobility not necessarily present.  An idiom describing this, in a voluntary situation, would be drawing the short straw, thereby acquiring some unpleasant or dangerous duty. An idiom for an involuntary situation would be getting thrown under the bus.  Context  Friend: I knew someone would eventually need to refactor this code. I didn't think it would be me.  Me: You're our... uh, what's the word?


Is there a keyboard shortcut to close a window in Windows?

I have always wondered if there was and this would improve my productivity manifold times.


Where should the apostrophe be placed in "Goats Milk"?

Milk from goats is available in supermarkets. On the shelves of our local store in England, I have found cartons boldly labelled all three of     Goats Milk   Goat's Milk   Goats' Milk   Most brands use no apostrophe at all, which does not seem right. Brands which use "Goat's" seem to imply that the milk comes from precisely one goat, which seems unlikely. Brands which use "Goats'" may have it right; however, every molecule of milk in the carton did, originally, come from precisely one goat, a molecule of a goat's milk.  Is there any hope of finding a "correct" position for the apostrophe in this case? Must we forever live with this example of the greengrocers [sic] apostrophe?


When using a book class (memoir), text shifts from left to right on each page

I'm very new to latex, and I've noticed that using a book class causes the text on one page to be on the right and then left on the next and so on. I'd like for it to all to be on the left or centered. How can I change this?


It’s my turn. It is a two handed game of Canasta. I have three cards left in my hand. There is only one card left in the Stock pile. Can I pick up the one card and play my hand?


I found this integral   And the person says this equals $ \frac{\pi ^2}{12}$  But I tried to solve this and could not do it and I was unable to find any thing online.   I tried many ways but could not even go through variable transformation by assuming ${(x^x)}^{{(x^x)}^{.^{.^.}}} = t$  How should I proceed?


I have two questions regarding hosting livecam broadcasting websites:   What is your advice for where to host sites like this? What are the hosting requirements?   I need to build a "clone" of chaturbate or cam4 for a client. I know these are not 100% legal websites. Therefore, I need an advice to warn them about hosting issues.  1. WHERE ?  What are the most secure and popular hosting providers, which TOS will allow hosting websites on their servers.  2. HOW ?  What are the requirements. I have never built a site like this. And as this is broadcasting live cam website - I suppose it has some requirements as RAM, Banwidth or maybe VPS... Can you tell me which one? Or maybe to give me some hosting package that will be enough for running this.


placement of "a" after an adjective that modifies a noun

“The U.S. is too immature a society to be allowed to play with guns. It has never shed its Wild West mythology.”   Why is not "a" put in front of "too immature"?What is the explanation for this?  I would write this sentence as "The U.S. is a too immature society ...."


I created a test Opportunity -       Opportunity Opp = new Opportunity();     Opp.Name = 'Test Opportiunity ';     Opp.AccountId = acct.id;     Opp.Business_Line__c = 'Capital Markets';     Opp.Result_Reason__c = 'Amenities';     Opp.CloseDate = System.today();     Opp.StageName = 'Qualified';     Opp.LeadSource = 'Web';     Opp.Type = 'New Customer - New Business';     Opp.Product_Type_Interests__c = 'ActiveDisclosure';     insert Opp;   and then created the controller and passed onto my class:  ApexPages.StandardController sc = new ApexPages.StandardController(Opp); AssociateECPController   ac = new AssociateECPController(sc);  PageReference myVfPage = Page.AssociateECP; Test.setCurrentPage(myVfPage);  // Put Id into the current page Parameters ApexPages.currentPage().getParameters().put('id',Opp.Id); String id = ApexPages.currentPage().getParameters().get('id'); System.assert('true',id==null);   and Put Id into the current page Parameters:  ApexPages.currentPage().getParameters().put('id',Opp.Id);   However when I run the test class the id is coming as null in the actual class and I'm not able to cover the if part.  Any ideas?


Ruby - how different are modules from classes?

Let me write down some difference between them as I know   Modules can't be instantiated, whereas classes can be Multiple modules can be included / extended, whereas only one class can be inherited   Aside from the above mentioned two, I don't see any other differences between them   Both can have class level variables (@@) Both can have class-instance level variables (@, initialized directly in the module/class) Both can have instance variables (@, initialized inside the methods) Both can have global variables ($) Both can have methods that can be directly called using their names (prefixed with "self") Both can have inner classes A class that includes and extends a module has access to all its methods (non-private) which is the same as inheriting from a class does for the subclass   Leaving the multiple inheritance out, is the only difference between classes and modules are that of creating objects?  (I don't have a lot of experience in Ruby, just trying to get my head around the difference between classes and modules. Please feel free to point out anything that I might have missed)


Minimal prime ideals are made of zero-divisors

Let $R$ be a commutative ring with unity which is not an integral domain. Let $P$ be any minimal prime ideal of $R$. How can I show that $P⊆Z(R)$, where $Z(R)$ denotes the set of zero-divisors of $R.$


Command used: dd  if=source.img of=/dev/sdb bs=16k The image (BSD-based OS) was written without errors, but I could not boot from it. When I tried to write a different image, the USB stick was not recognized (neither Arch linux, nor Windows 10). Diagnostic info: lsusb   [ 5964.379014] usb 1-1: new high-speed USB device number 19 using xhci_hcd [ 5964.519293] usb 1-1: New USB device found, idVendor=ffff, idProduct=1201, bcdDevice= 0.00 [ 5964.519299] usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0 [ 5964.521311] usb-storage 1-1:1.0: USB Mass Storage device detected [ 5964.521815] scsi host6: usb-storage 1-1:1.0    Neither fdisk nor parted nor lsblk list the device. Any ideas? Addendum 1: lsscsi --long [6:0:0:0]    disk    NAND     USB2DISK         0.00  /dev/sdb    state=running queue_depth=1 scsi_level=5 type=0 device_blocked=0 timeout=30


Any download command is terminated with this error - "Errors were encountered while processing: linux-image-4.15.0-20-generic"

Reading package lists... Done Building dependency tree        Reading state information... Done The following packages were automatically installed and are no longer required:   android-libext4-utils android-libselinux android-libsepol libf2fs0 Use 'sudo apt autoremove' to remove them. The following additional packages will be installed:   libappindicator1 libglade2-0 libindicator7 Suggested packages:   indicator-application The following packages will be REMOVED:   linux-image-4.15.0-20-generic The following NEW packages will be installed:   libappindicator1 libglade2-0 libindicator7 linuxdcpp 0 upgraded, 4 newly installed, 1 to remove and 255 not upgraded. 6 not fully installed or removed. Need to get 1,055 kB of archives. After this operation, 3,730 kB disk space will be freed. Do you want to continue? [Y/n] y Get:1 http://in.archive.ubuntu.com/ubuntu bionic/universe amd64 libindicator7 amd64 16.10.0+18.04.20180321.1-0ubuntu1 [21.7 kB] Get:2 http://in.archive.ubuntu.com/ubuntu bionic/universe amd64 libappindicator1 amd64 12.10.1+18.04.20180322.1-0ubuntu1 [19.4 kB] Get:3 http://in.archive.ubuntu.com/ubuntu bionic/universe amd64 libglade2-0 amd64 1:2.6.4-2 [44.6 kB] Get:4 http://in.archive.ubuntu.com/ubuntu bionic/universe amd64 linuxdcpp amd64 1.1.0-4 [969 kB] Fetched 1,055 kB in 1s (1,325 kB/s) (Reading database ... 170760 files and directories currently installed.) Removing linux-image-4.15.0-20-generic (4.15.0-20.21) ... /etc/kernel/postrm.d/initramfs-tools: update-initramfs: Deleting /boot/initrd.img-4.15.0-20-generic /etc/kernel/postrm.d/zz-update-grub: Sourcing file `/etc/default/grub' /usr/sbin/grub-mkconfig: 1: /etc/default/grub: If: not found run-parts: /etc/kernel/postrm.d/zz-update-grub exited with return code 127 dpkg: error processing package linux-image-4.15.0-20-generic (--remove):  installed linux-image-4.15.0-20-generic package post-removal script subprocess returned error exit status 1 Errors were encountered while processing:  linux-image-4.15.0-20-generic E: Sub-process /usr/bin/dpkg returned an error code (1)   After running cat /etc/default/grub:  If you change this file, run 'update-grub' afterwards to update # /boot/grub/grub.cfg. # For full documentation of the options in this file, see: #   info -f grub -n 'Simple configuration'  GRUB_DEFAULT=0 #GRUB_HIDDEN_TIMEOUT=0 GRUB_HIDDEN_TIMEOUT_QUIET=true GRUB_TIMEOUT=10 GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian` GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nomodeset acpi_oci=\"Linux\"" GRUB_CMDLINE_LINUX=""  # Uncomment to enable BadRAM filtering, modify to suit your needs # This works with Linux (no patch required) and with any kernel that obtains # the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...) #GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"  # Uncomment to disable graphical terminal (grub-pc only) #GRUB_TERMINAL=console  # The resolution used on graphical terminal # note that you can use only modes which your graphic card supports via VBE # you can see them in real GRUB with the command `vbeinfo' #GRUB_GFXMODE=640x480  # Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux #GRUB_DISABLE_LINUX_UUID=true  # Uncomment to disable generation of recovery mode menu entries #GRUB_DISABLE_RECOVERY="true"  # Uncomment to get a beep at grub start #GRUB_INIT_TUNE="480 440 1"


Is there a "Parallels Desktop" for Ubuntu?

I want to use "Parallels Desktop" in Ubuntu.  I did some searching and have found the archive Parallels.tgz. But I'm not sure if this is the right one.  How can I check whether I downloaded the correct archive and how shall I proceed?


Is there a difference between those expressions: "Die from cancer" or "Die of cancer"? Are they both correct?


I have to clean my laptop fans every 1 to 2 days

I have a gaming laptop, to be specific its a acer nitro 5. Every one to two day's I have to open it, clean it, and sometimes i put some WD 40 to make it less noisy. Sometimes the fan blades start to shake. I dont know what to do, I clean it every now and again. But still it always does the same thing, shake or make loud noises.


Why is DNS apparently involved in issuing "dir" on Windows 10?

For complicated reasons, I have been forced to make an identical copy of cmd.exe and rename it to cmd-2.exe, which I put as a shortcut on the Taskbar to have them "grouped" in different taskbar groups.  Sometimes, I forget about this, and to open a new cmd.exe I middle-click that Taskbar icon to open a new cmd.exe. I then type a command such as dir and it spits out a bunch of nonsense, including: DNS bad key, which only happens if I accidentally use cmd-2.exe, not if I open the "real" cmd.exe, so it's not a "practical" problem.  However, I wonder why that message is ever printed at all. Is it apparently failing to do some kind of DNS lookup or something? Why is DNS involved at all with issuing dir to list files on my local computer? I have no network set up, no cloud drives, nothing like that whatsoever. It scares me that (apparently) there are DNS queries being made when I issue dir.  Maybe DNS bad key refers to something completely unrelated to the Domain Name System? I don't know what a "bad key" would even be in that context.


Could someone please explain to me why the figure in my code is not appearing when I compile the code thanks.  MY CODE:  \documentclass{article} \usepackage{tikz,hyperref,multicol,lipsum,geometry,titlesec,fancyhdr,amsmath,MnSymbol,wasysym,fleqn}% \fancyhf{}% Clear all headers/footers \renewcommand{\headrulewidth}{0pt}% No header rule \renewcommand{\footrulewidth}{0.4pt}% No footer rule \fancyfoot[L]{*\href{myemail}{\emph{myemail}}}%  \usepackage{pgfplots} \pgfplotsset{compat=1.11}  \titleformat{\section}   {\normalfont\fontsize{12}{15}\bfseries}{\thesection}{1em}{}  \geometry{margin=1in}  \title{Title} \author{\textbf{myname}*}  \begin{document} \maketitle  \begin{abstract} Abstract \end{abstract}  \begin{multicols}{2} \thispagestyle{fancy}%    \section{Introdution}    some writing   \begin{figure} \begin{tikzpicture}     \begin{axis}[         xlabel=$x$,         ylabel=$\mu(x)$     ]     % invoke external gnuplot as     % calculator:     \addplot[smooth,samples=180,domain=0.0001:20] {1/(1+(1/x))};     \end{axis} \end{tikzpicture}  \end{figure}    some writing      \end{multicols}  \end{document}


Syntax error when adding a bool field to a struct (expected ‘:’, ‘,’, ‘;’, ‘}’ or ‘__attribute__’ before ‘=’ token)

typedef struct {   char fielda[ 2 ][ FIELD_A_MAX + 1 ];    bool fieldb = false;   bool fieldc = false;   sem_t fieldd; } Set;   I get the error:  error: expected ‘:’, ‘,’, ‘;’, ‘}’ or ‘__attribute__’ before ‘=’ token    bool fieldb = false;  What's my mistake here?


So I'm still a complete noob with Ubuntu but while I'm learning to code I just have it running on a VM (version 15.04 64bit), which is great no problems but I want to be able to take it with me. So I've been looking at basic laptops that I can fully install it on and found this that I quite like:  Would an install on this work? I've read some horror stories where Linux can mess peoples computers up and only work on certain brands. How true is this? Is it as daunting process as it sounds?  Many thanks guys :)


Settlers of Catan Cities and Knights: Can Longest Road Leave the Game?

Background In C&K, it is possible for your road length to decrease. If you have the longest road, and it gets shortened (by the Diplomat progress card or by an opponent's knight), what happens to the Longest Road card? The base game rules say the following:  The first player to build a continuous road (not counting forks) of at least 5 road segments receives the special card "Longest Road." If another player succeeds in building a longer road than the one created by the current owner of the "Longest Road" card, they immediately take the special card (and its 2 victory points).  And the C&K rules say:  Knights ... can be used to break another player's "longest road..." If the red player places his knight at 'B,' it will break blue's road, shortening his road for purposes of determining the longest road.  Consider the following situations Assume the rest of the other players' road lengths are too short to matter. In all cases, Player 1 starts with the longest road: a) Player 1's maximum road length is 7, Player 2's is 5. b) Player 1's maximum road length is 7, Player 2's is 6. c) Player 1's maximum road length is 7, Player 2's is 7. d) Player 1's maximum road length is 5, Player 2's is 5. e) Player 1's maximum road length is 5, Player 2's is 3. If in all scenarios Player 1's road is shortened by 1 length, who ends up with the Longest Road card? a) Player 1's road is still longer, so Player 1 keeps the Longest Road card. b) The two players are now tied, so Player 1 keeps the Longest Road card. c) Player 1's road is now shorter, so Player 2 takes the Longest Road card. d) Player 1's road is now shorter, so Player 2 takes the Longest Road card. NOTE: Player 1's road length fell below the 5-length threshold of earning the Longest Road card in the first place. But Player 2 still has a road of length 5, so there's no question: Player 2 takes the Longest Road card. e) What happens now? Does the Longest Road card get set aside, belonging to no player, or does Player 1 retain the card because no other player has (direct quote from the rules) "succeed[ed] in building a longer road than the one created by the current owner of the 'Longest Road' card?" Scenario e) According to what is written in the base rules, a player must take the Longest Road card for themselves in order for another player to lose the Longest Road card. There is no mechanism for the Longest Road card exiting the game because there is no way for road lengths to shorten, and thus no way for no player to have a maximum road length of less than five after any player has gained the Longest Road card. The C&K rules do not explicitly specify whether or not the Longest Road card stays in play. They simply say that knights can affect the length of a road; the Diplomat card rules also do not mention anything of use here. The interpretation that my friends and I have settled on is that Player 1 retains the Longest Road card until another player takes it away by having a longer road, regardless of whether or not Player 1's road length is still above 5. However, Catan Universe seems to disagree with us on this one... Does anyone have an official ruling for this? Thanks!


Find a surjective homomorphism of a group

I have difficulties with this task  Find a homomorphism $\Phi : (G, \circ) \to (G, \circ)$, that is surjective but not injective.  I tried to find such a homomorphism, by finding a surjective function, yet functions I tried were not homomorphisms. And then I end up with $Ker(\Phi)=\{e_G\}$. So I found an isomorphism.


What is the name of the perspective style of games like Final Fantasy 6, Chrono Trigger or Alundra?

What is the actual term for the 'top-down' style of the Super Nintendo games such as Final Fantasy 6, Chrono Trigger, et cetera. I'm looking for the equivalent term of:   'isometric' - (Jaggered Alliance, Final Fantasy Tactics, Fallout),  'first person' - (Half Life, Doom, Quake),  'birds eye' - (Grand Theft Auto) ? insert term here ? - (Final Fantasy 6, Chrono Trigger)


Is the linearity of Y and X an assumption for linear regression?

There are many posts regarding linear regression, so I'm sorry I'm still coming back to this subject. However, I still have some questions about it. I know for sure that the model should be linear within the parameters. That meaning we cannot have something like:  $$y = \beta_0 + \beta_1^2x_1$$  But I've read somewhere that the relationship between Y and X should be linear. Is this correct? If so, what does that mean? Does this mean that the relationship between Y and all $x$'s should be linear? If that is correct, why would $y = \beta_1 \cdot x^2$ be a linear regression model?


Normed, Finite Dimensional Vector Space are Complete

Given a normed, finite-dimensional vector space $V$, where we define the metric $d(x,y)=\|x-y\|$. Show that this space, under this metric, is complete - that is, every Cauchy Sequence converges.   I'm looking for, preferably, a linear algebra-based approach if possible. I've already tried writing this in terms of the basis and studying the coefficients. I also looked at the sequence $\| x_n\|$ but I haven't made much connections.


Where does Scripting ends and Programming begins? ActionScript 3 and JavaScript/JScript are so different...


Paradox with Gauss' law when space is uniformly charged everywhere

Consider that space is uniformly charged everywhere, i.e., filled with a uniform charge distribution, $\rho$, everywhere.  By symmetry, the electric field is zero everywhere. (If I take any point in space and try to find the electric field at this point, there will always be equal contributions from volume charge elements around that point that will vectorially add up to zero).  Consequently, from Gauss' law in the differential form  $$\nabla\cdot E = \frac{\rho}{\epsilon_0}$$  if $E$ is zero, the divergence is zero hence the charge density is zero.  What is going on here? is a nonzero uniform charge distribution that exists everywhere has no effect and is equivalent to no charge at all?


Limiting the number of GPS locations in MySQL query

I'm using the following query to get the next local events using their location. My database is growing and I've got events from all over Europe. So basically, the query calculates distances from events of two different countries (like Spain and Germany) which is really not useful since I'm looking for the next events within 20 KM.   # latitude & longitude are the fields in DB # 43.57 & 3.85 are given values representing the local test point SELECT ( 6366 * ACOS( COS( RADIANS( 43.57 ) ) * COS( RADIANS( latitude ) ) * COS( RADIANS( longitude ) - RADIANS( 3.85 ) ) + SIN( RADIANS( 43.57 ) ) * SIN( RADIANS( latitude ) ) ) ) dist FROM events HAVING dist >0 AND dist <=20 ORDER BY event_time ASC  LIMIT 0 , 5   So basically, this query is going to get all the distances of all the events before being able to use the HAVING.   Is there a better way?


Profile pictures on the profile page shouldn't be stretched

It looks like there's been a  in the profile picture system. However, that appears to have broken images which are not squares.  This is what I see on my profile page. It's horizontally stretched, and it looks quite ugly:        For comparison, here's the top bar, which looks fine.        I've seen other peoples' pictures which are stretched vertically presumably their pictures have landscape-oriented originals, while mine is in a portrait configuration.  I'm on Chrome 71.0.3578.98 for Windows 10.


I was doing some messing around on excel to answer this brain teaser:  In autumn the amount of leaves falling from a tree get doubled after every hour. The tree is leafless after 9 days. How many hours does it take until half of all leaves have fallen down?  WARNING: Brain teaser answer below, if you want to work it out yourself.  On Excel I was simulating doubling the number of leaves falling every hour, finding the cumulative leaves that have fallen, and then the proportion of the total leaves that have fallen (note 9 days = 216 hrs):  hour    leaves falling   cumlative      proportion of leaves         that hour                       that have fallen 1       1                1              9.49557E-66 2       2                3              2.84867E-65 3       4                7              6.6469E-65 4       8                15             1.42434E-64 5       16               31             2.94363E-64 .       .                .              . 211     1.6455E+63       3.29101E+63    0.03125 212     3.29101E+63      6.58202E+63    0.0625 213     6.58202E+63      1.3164E+64     0.125 214     1.3164E+64       2.63281E+64    0.25 215     2.63281E+64      5.26561E+64    0.5 216     5.26561E+64      1.05312E+65    1   It takes 215 hours for the first half to fall, and then the second half all fall in the final hour.  I can see this, but don't fully understand why this is.   What I can see is the second column is just the series $2^n$, where $n$ is the $hour-1$, and that the third column is one less than the next $2^n$, i.e.: $$ 2^{n+1} = 1 + \sum_{i=0}^{n}2^i $$  No doubt that, at hour 215, this 1 before the sum is so insignificant that: $$ 2^{n+1} \approx \sum_{i=0}^{n}2^i $$ for large $n$.  I can see therefore that, for all intents and purposes, half of the leaves do fall in the last hour.  My question is, why does: $$ 2^{n+1} = 1 + \sum_{i=0}^{n}2^i $$ Is there any intuitive logic that can explain this? Or, if not, a mathematical proof?


Two materials on one object - One metallic, One matte

First, I'm VERY new at this, so please bear with me.  What I'm trying to do is create a label on a bottle that has certain parts that are gold foil and the rest is somewhat matte. This is an actual bottle in real life that needs to be pretty exact. I will also need to make many multiple other bottles of different shapes/sizes, so the technique I use will need to be very efficient.   I started with the image of the label as one material UV unwrapped onto the object (label) and it looks pretty good, but the gold foil parts of the bottle need to look more metallic. And if I do that, it makes the rest of the label metallic looking. I've tried adding the gold foil parts as one image and the rest of the label as another image, but that doesn't work for two reasons: 1. the combined images aren't as sharp as using just one 2. I still can't make the gold foil and matte parts look like two materials.  I've tried every tutorial I can find, but none fit this exact example.


YA book with smiling girl on the cover with very long braid and an animal

Alright, so this is a fantasy book (I am eighty-five percent positive). Honestly I wish I remember something from the book, but all I remember is the cover. I read it in 2007.  The cover has a young girl on the cover who is surrounded by green. She has fair skin and brown hair that is in a ridiculously long braid. there may all be a small animal on the cover with her, I'm not entirely sure. She's smiling, but it's a soft smile.   The series is meant for young adults and is part of a series. If anyone at all could help that would be super! Thanks again!    Incorporating comments from OP:     It was a drawn cover, natural book. She was wearing a green top. She was only visible from just below her shoulders and up. There were green vines surrounding her, but all I remember of the background is green. I got it from my Aunt and I have no clue when it was written, but it seemed fairly new. Fantasy. I couldn't see how long the braid was, but I remember that it was described as longer than usual. No, it is not Rapunzel, I am 100% positive I would remember Rapunzel. It's not anything like Rapunzel.           After searching for a while longer, I remember that it is centered around the girl and she had a small animal with her, along with a bird. That's really all I remember. I contacted my Aunt about it, but I'm not sure she'll remember. It was part of a trilogy! The first book is as described and the second all I remember is that she was somewhere near the sea.


How to prove for a finite group that $| \langle g \rangle|=o(g)$?

How to prove for a finite group that $|\langle g \rangle|=o(g)$?  I really don't know how to show that this is true I tried to say let $o(g)=m$ and then show that $|\langle g \rangle|$ has exactly $m$ elements but I wasn't even sure it did because it would contain the elements $g^0,...g^{m-1}$ so that would mean it's true but what about $g^{-1}$ and the other elements with negative coefficients so it seems like it would actually be bigger than $m$?  Thanks.


Skyrim crashes on start. Do I need a new sound card?

In my computer I have both a Sound Blaster Live! 5.1 SB0220 card and a Realtek ALC850 chipset on an  motherboard. My game crashes on launch, just after the Bethesda logo fades. I've tried both cards with multiple drivers, with the same results.  I've seen the workaround which involves changing the audio sample rate to 16bit 44100Hz, but to the best of my knowledge, both cards seem to only support a 16bit 48000Hz sample rate. Are there any other workarounds, or does Skyrim simply not support my hardware?


Two column figures with figure* - bottom on same page - figure numbering wrong

So in order to have a full width figure on the bottom on the same page we have to move the figure to the previous page. But given that we have a figure before this, which is also referenced before it, we have to move to this too in order to keep the numbering of the figures in order.  However, the figure we took with us for may now appear on previous page instead of at the location we wanted it.  Anyway to get around this?  I tried the \afterpage{} which put the figure on right page but the numbering is still wrong.  Code example:  \documentclass[12pt, a4paper, twocolumn]{article} \usepackage{blindtext} \usepackage[utf8]{inputenc}  \begin{document} \blindtext \blindtext \blindtext  \begin{figure}     \includegraphics{OneColumnFigure.png}     \caption{OneColumnFigure} \label{fig:label} \end{figure}  \begin{figure*}[b!]     \includegraphics{TwoColumnFigure.png}     \caption{TwoColumnFigure} \label{fig:label} \end{figure*}  \blindtext \blindtext \blindtext  \end{document}   This will make our OneColumnFigure appear on the same page on the desired location, but our TwoColumnFigure will appear on the next page on the bottom which is not where we want it:    If we move TwoColumnFigure to previous page, the layout will be correct but the figure numbering wrong:    And if we move both figures to the previous page, the numbering will be correct but the layout wrong:


Is is possible to convert a .vdi file into a .iso that can be burned to a cd or dvd and make it like an installer. Or Is it possible to convert virtual machines to physical environments?


When i save my illustrator poster the black background turns to white

My poster has a black background with text and images (font in colour white) on the top. When i save the poster only the images appear and the background has turned white, subsequently the font which was white over the top disappears. How do i save the illustrator poster with a black background? Thank you


I have a graphic for my company & I need it to be made larger so that the sign company can grow the image without loosing quality. How do I do that? I downloaded Alien Skin Software because I heard that the software would be able to help. I don't have Photoshop so I am looking for something easy. All help would be appreciated.


View the assembly code for C source code through gcc in the terminal

I run gcc -S filename.c or gcc filename.c -s successfully but no output. So how do you view the assembly code itself?


How do you create a windows 8 tile to connect to a VPN?

This is too deep in the charms since I use it constantly. I would like a tile that would either connect to the VPN or a tile that will open the network connections options within the charms menu.  I have the 8.1 preview installed so I can use Outlook to connect to my work Exchange account. This requires VPN, so this is why I will be connecting to the VPN constantly.


Why are "magnetic field lines" called "lines of force" when they are perpendicular to the direction of force?

Why are "magnetic field lines" called "lines of force" when they are actually  perpendicular to direction of force (Lorentz force,cross product)?    It makes sense to call "field lines" as "lines of force" in case of fields like gravitational, electrostatic, etc., but not in magnetic force it seems to me.


I want to install some plugins for gedit, and I need to know my gedit version to install the correct plugins. How do I check it?  Note: I'm running Ubuntu 16.04


What can I do if one coauthor tries to prevent a journal paper from being published?

I was a PhD student and was supervised by one bad supervisor. Our relationship broke up at the time when I tried to graduate. After a "fighting", I successfully graduated. But I left 10 unpublished paper to him. I had no time to publish these paper before I graduate. I put my supervisor's name there because he was my supervisor. I didn't really contribute to the paper.   I'm sure the 10 paper can be published as high quality journal paper because I'm currently working as a staff in another University. I've published a lot paper expect for those 10 so I know what paper can be published. But as the coauthor, my ex-supervisor "refused" to publish these paper. He always told me he needed to have a look, and nothing else happened. Every time I contact him, he would propose some unreasonable questions or tell me to wait for some time to put off the publication and no reply at all after that. It has been 2 years up to now. None of my 10 paper has been submitted yet. He obviously doesn't need the paper as a professor, but I need them desperately as a new lecture.   I've waited for 2 years for the first out of the 10 paper to be submitted. I couldn't wait for 20 years for the 10 paper to be submitted. He doesn't say he want to delete his name from this paper but I have sufficient reason to believe that he doesn't want me to publish these paper. He warned me that I couldn't submit the paper without his agreement otherwise he would withdraw the paper. My question is can I kick him out from the coauthor list and publish the paper by myself? Or is there any other suggestion say contacting the University about this situation to solve the problem?   I'm quite annoying as if I couldn't get rid of him even after I graduate and got my own position. Can anyone help please. Thank you in advance!


I upgraded to Ubuntu 18.04.  Now I would like to change the clock looks.  Up to now it looks like this:    I would like to see dd.mm to see the date of today.  How to do this?


Multiple IPv6 addresses added to interface, now IPv6 not working on my server

I got /64 IPv6 block from my server provider.  When I add few IPv6 addresses (maybe 10 or 20) to network interface. Everything works fine about IPv6 network.  When I'm added above 500+ IPv6 addresses to network interface. My server IPv6 network not working.  I'm used to this type of command line to add IP address to network interface.  sudo ifconfig em1 inet6 add 2001:bd8:24ac:36c8::/128   I need to use at least 1000 IPv6 addresses on my server.  Please help me, how to solve this issue?  Note: I'm using Ubuntu 14.04 64-bit server  Thank you.


How reliable is to be + past participle to identify passive voice?

I am trying to write a software that can identify simple variants of passive voice in an english sentence.  I found multiple resources that state that to be + a past participle is an indication that the sentence is in passive voice.  My question is, is this a reliable rule? Are there any false positives, i.e. are there sentences that contain a construct of to be + past participle that are not in passive voice?


Some time ago I came across a problem which might be of interest to the physics.se, I think. The problem sounds like a homework problem, but I think it is not trivial (i am still thinking about it):  Consider a rail tank wagon filled with liquid, say water.  Suppose that at  some moment $t=0$, a nozzle is opened at left side of the tank at the bottom. The water jet from the nozzle is directed vertically down. Question:    What is the final velocity of the rail tank wagon after emptying?    Simplifications and assumptions:     Rail tracks lie horizontally, there is no rolling (air) friction, the speed of the water jet from the nozzle is subject to the , the horizontal cross-section of the tank is a constant, the water surface inside the tank remains horizontal.    Data given:    $M$ (mass of the wagon without water) $m$ (initial mass of the water) $S$ (horizontal cross-section of the tank) $S\gg s$ (cross sectional area of the nozzle) $\rho$ (density of the water) $l$ (horizontal distance from the nozzle to the centre of the mass of the wagon with water) $g$ (gravitational acceleration)    My thinking at the moment is whether dimensional methods can shed light on a way to the solution. One thing is obvious: If $l=0$ then the wagon will not move at all.


Is it possible to add Yakkety or Zesty repositories to Ubuntu 16.04?

So, is it possible to add Yakkety or Zesty repositories to Ubuntu 16.04? I mean I would like to add something like this deb http://cz.archive.ubuntu.com/ubuntu zesty main universe to sources.list file. Will I get errors or another problems with packages? My current system is Ubuntu 16.04.


Words pertaining to the senses and the corresponding disabilities

I need help on finding words relating to the senses/perception. I mean this in a neuronic/biological or philosophy-of-mind kind of way.  A word for...   pertaining to the senses (Is it sensory?)  pertaining to vision (ocular?) pertaining to smell (olfactoric?)  pertaining to taste     pertaining to sound  pertaining to touch unable to smell  unable to taste     unable to feel/touch  unable to perceive (unconscious?)  (unable to see: blind) (unable to hear: deaf)


Ubuntu 16.04 - Could not get lock /var/lib/dpkg/lock

So far the best way to get it working without breaking a possible background running installation ( as it could happen by removing the lock file), is stopping the service using apt:  Error:  # sudo apt-get upgrade E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable) E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?`   Solution:  sudo systemctl stop apt-daily.timer


I'm going to The Netherlands (as usual) and was wondering if the times overlapped. For example, I went for about a month in December and am planning to go again this May.   Assuming my 180 days began when I went in December, I will be okay to go again in June?    If I'm already there, will my 180 days reset or will they count my second vacation as going over the amount of days I'm able to stay there?