The screenshot is taken from the book Elementary Analysis : The Theory of Calculus by Kenneth A.Ross (1st Edition). Can anybody guess the font here. I am guessing that the font used is ITC Veljovic LT Book but I am not sure. Secondly, how do we use this font in LaTex. Is it possible? Adding another screenshot, to get a view of the font.


form_state->setRedirect(to_a_new_node_page) from the submitForm function, route "does not exist" issue

I created a custom module, It generate a custom Form in a page. When I submit my form, I create a new node. So, I am redirect to the form page but I would like be redirect to the new node page.  I add this line at the end of my submitForm function :   $form_state->setRedirect('node/'.$mynewnode->id());   But when I submit my form from the website, I get the empty-white-screen-of-the-death. My apache log :   ... Uncaught PHP Exception Symfony\\Component\\Routing\\Exception\\RouteNotFoundException: "Route "node/153" does not exist. ...   And then, when I go manually to the node/153 page, there isn't any problem. The page work well.   My question : where is my mistake ? How can I set the redirection after create the new node ? Is it possible from the submitForm function ?


How can time dilation occur for one person but not another?

I have heard of the thought experiment where someone fly off in spaceships and come back younger than their twin on earth.  But a fundamental idea behind general relativity was that motion can only be described as relative to others. Therefore, the twins would have the same relative acceleration to each other.  If we think about them as floating in space, there should be no way to tell who is doing the accelerating. So how does physics determine which one ends up younger?


I have the following XML document:  <projects>   <project>    <name>Shockwave</name>     <language>Ruby</language>     <owner>Brian May</owner>     <state>New</state>     <startDate>31/10/2008 0:00:00</startDate>    </project>   <project>    <name>Other</name>     <language>Erlang</language>     <owner>Takashi Miike</owner>     <state> Canceled </state>     <startDate>07/11/2008 0:00:00</startDate>    </project> ...   And I'd like to get this from the transformation (XSLT) result:  Shockwave,Ruby,Brian May,New,31/10/2008 0:00:00 Other,Erlang,Takashi Miike,Cancelled,07/11/2008 0:00:00   Does anyone know the XSLT to achieve this? I'm using .net in case that matters.


Why I can use @list to call an array, but can't use %dict to call a hash in perl?

Today I start my perl journey, and now I'm exploring the data type.  My code looks like:  @list=(1,2,3,4,5); %dict=(1,2,3,4,5);  print "$list[0]\n";         # using [ ] to wrap index print "$dict{1}\n";         # using { } to wrap key  print "@list[2]\n"; print "%dict{2}\n";   it seems $ + var_name works for both array and hash, but @ + var_name can be used to call an array, meanwhile % + var_name can't be used to call a hash.  Why?


In Triangle, $\sin\frac A2\!+\!\sin\frac B2\!+\!\sin\frac C2\!-\!1\!=\!4\sin\frac{\pi -A}4\sin\frac{\pi -B}4\sin\frac{\pi-C}4$

To prove  $$\sin\frac A 2+\sin\frac B 2+\sin\frac C 2-1=4\sin\frac{\pi -A}4\sin\frac{\pi -B}4\sin\frac{\pi-C}4$$  My approach :   $$ \begin{align} \text{L.H.S.} & = \sin\frac{A}{2}+\sin \frac{B}{2}+\sin\frac{C}{2} -1 \\[8pt] & = 2\sin\frac{A+B}{4}\cos\frac{A-B}{4}+\cos\left(\frac{\pi}{2}-\frac{C}{2}\right)-1 \\[8pt] & = 2\sin\frac{\pi -C }{4}\cos\frac{A-B}{4} - 2\sin^2\left(\frac{\pi -C}{4} \right) \\[8pt] & =2\sin\frac{\pi -C }{4}\left\{ \cos\frac{A-B}{4} - \sin\left(\frac{\pi -C}{4} \right)\right\} \end{align} $$  Unable to move further please help. thanks.


How can I disable the drag handle on the desktop?

Any idea how the ability to "drag" the desktop app can be turned off? I'm talking about the area in the top-middle of the screen that changes the mouse cursor when you hover over it. On metro apps it makes sense, but on the desktop more often than not I end up inadvertently dragging the desktop somewhere when trying to select icons.   Screenshot:    If it can't be turned off for the desktop only, can it be disabled globally?


How to run local shell script on remote server via SSH?

I want to run a local shell script on a remote computer with SSH.  How can I do this?


Query for Contacts on Accounts in Execute Part of Batch

List<Account> Scope = [SELECT id FROM ACCOUNT]; // This is the query being used  global void execute(Database.BatchableContext BC, List<Account> scope)      {            List<Account> accounts = [SELECT id, (SELECT outreach_status__c,Initial_Contact__c, Champion__c, Finance_DM__c, Operations_DM__c, Executive_Sponsor__c ,LastActivityDate FROM Contacts) FROM Account WHERE Id in :scope]; }   Or is it  List<Account> Scope = [SELECT id FROM ACCOUNT]; // This is the query being used      global void execute(Database.BatchableContext BC, List<Account> scope)      {            List<Account> accounts = [SELECT id, (SELECT outreach_status__c,Initial_Contact__c, Champion__c, Finance_DM__c, Operations_DM__c, Executive_Sponsor__c ,LastActivityDate FROM Contacts) FROM Account WHERE Id = :scope]; }   Basically I am not sure if I should use "ID IN :Scope" or "ID = :Scope". I am asking this because I am finding that not all records are being processed.


How many attacks do I get with a ready action?    I normally get two attacks in an action, an action surge attack(when I use an action surge), and a bonus action attack. If I ready an attack so that it triggers when an enemy appears, how many attacks do I get?  I take it the action surge and bonus action can't be readied, but since the readied action is now a reaction, do I still get my two attacks?


Recently I was looking at the X-Men box set and saw that currently five have been released.  I had it in my head that these would be called a quintology but I have seen them being called a pentalogy.  I assume both words are interchangeable, but is one of the terms preferred over the other, or is it a matter of taste?


Who does Gimli meet at the eaves of Fangorn?

From The Two Towers, Book 3, Chapter 2, The Riders of Rohan:  Suddenly Gimli looked up, and there just on the edge of the firelight stood an old bent man, leaning on a staff, and wrapped in a great cloak; his wide-brimmed hat was pulled over his eyes...[Aragorn] strode forward, but the old man was gone. There was no trace of him to be found near at hand, and they did not dare to wander far.  Later on we have (Chapter 5, The White Rider):  'Wait a minute!' cried Gimli. 'There is another thing that I should like to know first. Was it you, Gandalf, or Saruman that we saw last night?' 'You certainly did not see me,' answered Gandalf, 'therefore I must guess that you saw Saruman. Evidently we look so much alike that your desire to make an incurable dent in my hat must be excused.'  But if it was indeed Saruman, why did he simply observe the three companions and then disappear? Gandalf says to Gimli in Chapter 10, The Voice of Saruman:  'I will come,' said Gimli. 'I wish to see him and learn if he really looks like you.' 'And how will you learn that, Master Dwarf?' said Gandalf. 'Saruman could look like me in your eyes, if it suited his purpose with you.'  So why did not Saruman question the three if it really was him? At that point in the story he was surely in need of knowledge of the orc host and their captives. Throughout the book Frodo has visions of things happening (or about to, or have done), so could this have instead been a vision of Gandalf they saw, as a premonition of his return? Is there anything explaining or shedding more light on this?


Ubuntu 16.04 keeps saying 'out of boot space'

Every time I boot or log in I get system message that says there is no more free space left in the boot partition.  There is 384MB in the boot partition.  Yes, they appear all used up when using the disk analyzer tool.  There is nothing I did consciously to cause this.  It is a single boot system with nothing fancy loading on startup.  How to allocate more space on this boot partition?  Which set of commands or tools should I use?


Removal and delete of duplicate records in my table

I have this table:  id  |  Name  | Age ================== 1   | AAA    | 22 1   | AAA    | 22 2   | BBB    | 33 2   | BBB    | 33 2   | BBB    | 33 3   | CCC    | 44 4   | DDD    | 55   I need to delete from this table all the duplicate records and leave only one record.  The table will looks like this:  id  |  Name  | Age ================== 1   | AAA    | 22 2   | BBB    | 33 3   | CCC    | 44 4   | DDD    | 55   I work with SQL Server CE for Mobile  Thanks


X Windows special programs: do some of these still exist?

I recall that X11 provided a number of "fun" programs accessible via unix. For instance, if you use the command xeyes, an interface will pop up of cartoon-like eyes which follow your cursor everywhere.   This still works on my most update version of X11.   But I remember so many more of these fun little commands. For instance, there is:  (A) xsnow which causes snow to fall on your desktop, with the santa option  (B) xsol which would begin a solitaire GUI you could interact with   (C) xmille was something similar, and allow you to play the game Mille Borne  (D) xroach caused cockroaches to crawl all over your screen, with the squish option allow you to click/squish these buggers  (E) xphoon would show the moon as it appears today  (F) xpenguins has penguins appear  (G) oneko had something to do with cats and dogs  Question 1: Does anyone else still use these? The only command which still works for me is xeyes. Which updates do I need to use the others?   Question 2: Have I forgotten any of these types of X11 commands?


Find possible number of triangles with integer sides for a given inradius

inradius = $5$ possible triangle sides $(25, 20, 15)$ $(37, 35, 12) (39, 28, 17)$ ...  Find formula to find other possible sides of triangles.


How to choose value of resistor in voltage divider?

I understand that the output voltage is determined by the ratio between the two resistor values, and that if the both resistors are same then output voltage will be exactly same for all; but what's the basis of picking the resistor values?there is any need of consider output current to choose resistor value.


Why is file transfer speed decreased when copying multiple smaller files?

Let's say I'm copying a portable apps directory from PC to an external HDD. An application.exe file is around 4 megabytes in size, but most other files are only tens of kilobytes in size, and most of those files take longer to copy/move than that bigger file having 4 megabytes.  Why is this?


How do I stop friends from getting notifications about what I do on Facebook?

Friends and family (who are not in my Close Friends group) are getting notifications when I post or like something on Facebook. How do I stop this?


Find the limit $\lim_{x\to 0}\frac{\sqrt[5]{1+\sin x}-1}{\ln(1+\tan x)}$. I tried subtracting $1$ for using $\lim$ of $e$ but I realized that this is not a problem that can be solved in that way. Using only algebra, famous limits without L'Hôpital.


Small input trouble in a program in java

I have learnt about BufferedReader as well as BufferedWriter, so I decided to create a small text processor for the command line (meaning without interface, just in cmd/terminal). It asks a user for document name (Which will then create a file) and then user can type sentences. Each time user presses "enter" button, text is entered into the file and new line is created and then allowing user to type more. At the end, it will display a message saying file is created. NOW, I have encountered a problem where user would not be able to stop the process of entering data and creating file, because the program kept creating new lines despite entering nothing or quit keyword(which i stated in the code in order to quit the program.) Here is my original code:  import java.io.*; class TextProcessor { public static void main(String[] args) {     try     {     System.out.println("Please enter name of the file");     BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); //User input     String file = in.readLine();     BufferedWriter writer = new BufferedWriter(new FileWriter(file)); //Creating file as well as instance for inputting text to the file.       System.out.println("Enter text");     String line = "";      do     {         line = ins.readLine();         System.out.println(line);         writer.write(line);         System.out.println("Second " + line);         writer.newLine();     }     while(line != "quit()");     //while(line != null);       in.close();     writer.close();       System.out.println("Text is created with entered text");     }     catch(IOException e)     {         System.out.println("Error occured");     } }   }  However, I found a solution to this, which is replacing do-while block with while one:  int counter = 0;     while(counter != 1)     {         line = in.readLine();         writer.write(line);         if(line.equals("quit()"))         {             ++counter;         }         else {writer.newLine();}     }   I have a question about this now, why can't I use do-while statement instead of while, even if it seems logical that the program would work? Thank you for reading this!!!!  P.S. I also wonder if I can bring small improvements to this or any other way creating this type of program. Thanks if you give feedback!


If I have $1$ jar of $20$ balls with $10$ red, $5$ blue and $5$ yellow, $1$ jar of $30$ balls with $10$ red, $10$ blue and $10$ yellow and $1$ jar of $50$ balls with $15$ red, $20$ blue and $15$ yellow, but I can only pick three from each jar. How many permutations of balls can I get if the order is important?  As shown in this rough sketch    Attempts: $\frac{20!}{(10!\times5!\times5!)} + \frac{30!}{(10!\times10!\times10!)} + \frac{50!}{(15!\times20!\times15!)} = 7.31\times10^{21}$


If $x$ and $y\in\mathbb R$ are computable, is $x+y$ computable?

I know that a real number $x\in \mathbb R$ is computable if there is a computable function $f:\mathbb N\rightarrow\mathbb Q$ such that, for all $r\in\mathbb N$, $|f(r)-x|≤2^{-r}$. I'm 99% confident that yes, $x+y$ is computable here, but am having difficulty formally proving this with confidence.


continuing equation under the equal sign

how to continued the equation under the equal sign?    I want to do it like this


Allow moderators to fine-tune the effects of a lock

Current Situation  When a moderator locks a question or answer, they can choose between different types of post notices: content dispute, off-topic comments, historical significance, wiki answer, or no notice. , but that it works this way is not clear to moderators and it is also not clear what effect a given notice has. The only way to find out for sure is to ask somebody who is not a moderator or use a sock. (This is due to moderator powers possibly overriding the effect of locks.)  Feature Request  Store the effects of a lock separately independent of the post notice. In the interface for locking a post, provide moderators with a checklist regarding the effects of the lock, for example:     This lock prevents:         answers   votes   flags   comments   edits      For questions, also add an option to apply the same lock to all answers to the question. For the canned lock reasons, automatically provide an appropriate choice as defaults.  At the very least make it clear in the dialogue what detailed effects a lock has.  Rationale  Post locks are used rarely, but when they are it is often for important reasons such as avoiding a divide of the community, an escalation of events, or similar. Thus, locks are a tool which moderators have little experience with, but whose correct use (i.e., choosing the right type of effects and knowing what the effects are) may be crucial. Moreover, many locks are used for special cases with individual needs, which in turn require individual locks.  In a specific example, there is a question on Academia, which lead answers and comments, whose appropriateness for the site is subject to a Meta discussion. To avoid further potentially inappropriate comments, answers, etc., I wished to lock question for the remainder of the Meta discussion. I chose content dispute as a lock reason, since it seemed most appropriate notice, however this only prevented edits to the question – which makes sense in other cases but not here. After I noticed this, I chose a historical lock (which I knew to be affecting everything) and removed the post notice (because it was not appropriate). The latter action lead to comments on answers being allowed (), which was not the desired effect either.  Related Questions    – This seems to be partially addressed: The different locks already do have different effects. However, my request goes further than this.  – This is about customising the notice not the effect.  – This would be addressed with this.


Should I quote Wikipedia if I can't rephrase it?

I want to write down this idea that I get from Wikipedia: both (James Watson and Francis Crick) thanked the Schroedinger's book for their inspiration.  (More specifically, that page is , and that idea comes from the last sentence of the second paragraph.)  This is what the wiki writes:     each respectively acknowledged the book as a source of inspiration for their initial researches.   Of course that statement has a reference back up. My problem is that I can't figure out how to write that idea down without using the exact one used by the wiki. In my opinion, that sentence is better than any sentence I can think of to rephrase it. If I just use it anyway without quoting it, I'm afraid that I will be plagiarism. If I say that it is from Wikipedia, well, you know the result. My best solution I can find is using this clause:     stated by Wikipedia, with Julian F. Derry (2004) backs up   But it is super awkward. In case I can't think of any better sentence, do you know how should I do?


What is the scientific name of this evergreen plant?

This plant is found in India. It is an evergreen plant. Would love to know the scientific name.


How i can get the label of the selected value in Combobox - Lightning Web Components?

I'm developing a LWC Combobox and I want to get the label of the selected value in the handleChange() method, not the id. I filled the combobox with JSON Items in this form :   {value :'Id', label:'Label'}   I used this in JS : event.detail.value but it gives the id not the Label.


Globally recording Bash history: Dealing with long-running commands

For security reasons, I'm trying to remotely log all commands that users enter into the shell.  I've got it to work by using this in my global bashrc:  PROMPT_COMMAND='history -a >(tee -a ~/.bash_history | logger -t "$(basename $SHELL)[$$]: ($USER)")'   However, each command is getting recorded only after it has completed.  For long-running commands such as sudo su or mysql or even sleep 7000 && /bin/do_something_risky, this is a problem.  So my question is: How can I log commands at the beginning of execution rather than at the end?  Is this possible without something really painful such as hacking the Bash source code?  (Yes, I know a user could turn off this logging by overwriting PROMPT_COMMAND, but we'd know something was up if they were opening shells but nothing was getting recorded.)


Using $\sin()$ or $\cos()$ for computing SHM?

In simple harmonic motion, you can use either the sin or cos form of the equation but my question is which one do you use when and why?  I am having a tough time understanding this, so any help would be thoroughly appreciated


I'm trying to do a dual boot in Arch, I install Arch how is recommended in the official guide but when I run os-prober don't find Ubuntu. The partition where is EFI "Ubuntu" is the same partition for EFI "Arch".      But os-prober in Ubuntu works and Find Arch without problems.


Unexpected characters like â€™ are found in database

While trying to figure out possible reason for the error, the reason seems to be encoding some where in my web app. The strings look fine when I checked them by using var_dump but upon insertion into the database, I see this characters in my table. I am using PDO for executing SQL queries.  var_dump($string); // the string looks fine here ex- Shopaholics’  // function to create db connection     function db_connect() {             if(self::$db_con === null) {                 $db = self::$databases[self::$use_db];                 self::$db_con = new mysqli($db['hostname'], $db['username'], $db['password'], $db['database']);                 self::$db_con->set_charset('utf8');             }             return self::$db_con;     }     // code to insert into Db    $con = db_connect();    $stmt = $con->prepare(INSERT INTO case_study (case_id, description_case)            VALUES (NULL, :description));    $stmt->bindParam(:description, $description);    $stmt->execute();


Is there an in universe explanation as to why the alternate universe is more advanced than ours?

In Fringe, it's revealed that there's an alternate universe that is almost identical to ours only they are more technologically advanced.  Is there an explanation as to why the alternate universe is about 30 years ahead of ours? As in where did the timeline diverge from our own?


I'm having problems joining three tables. It works well when I use the same query for joining two tables (after removing LEFT OUTER JOIN C ON B.No = C.No). However, it doesn't work when I use three tables.  This is my query  SELECT A.Name, B.Quantity, C.Quantity  FROM A  LEFT OUTER JOIN B      ON A.ID = B.ID  LEFT OUTER JOIN C      ON B.No = C.No;


Late 80's early 90's sci-fi choose your own adventure

There was a choose your own adventure book that I read sometime in the late 80's, early 90's. I live in Northern Virginia, if that helps. Anyway, the story was science fiction - possibly a different universe, as none of the characters looked human (other than shape) and the locations didn't look like earth.  I remember a complicated maze that the protagonist had to go through. Also, the protagonist looked kinda like a power ranger, but this definitely wasn't power rangers. I believe it was black and white. I remember, maybe space ships - as in at the end of the adventure maybe the protagonist took off?  I've been looking for this book for decades. I believe it was part of a series of choose your own adventure books (as in publisher, the books themselves were not related to each other, just the look/style).


100x less insert performance with Galera multi-master

I am running an application which inserts a lot of rows and we were experiencing some low performance. So i started benchmarking the Galera Cluster with sysbench and oltp_insert.lua (practically inserts with random key).  The performance of the cluster is really bad.   With the same test:    As a standalone DB i can perform about 35000 tps  With Galera multi-master the performance is: 350 tps   The table structure is this one:         Table: sbtest1 Create Table: CREATE TABLE `sbtest1` (   `id` int(11) NOT NULL,   `k` int(11) NOT NULL DEFAULT '0',   `c` char(120) NOT NULL DEFAULT '',   `pad` char(60) NOT NULL DEFAULT '',   PRIMARY KEY (`id`),   KEY `k_1` (`k`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1   What i tried so far (with no success):   increase wsrep_slave_threads=16 no matter how many client threads i use, the TPS is still 350 (looks like the transactions are serialized somehow by the DB) set wsrep_sync_wait=0 (although i perform no reads) the db does not use binlog, its not enabled.   Configuration:  [mysqld]    binlog_format=ROW    innodb_autoinc_lock_mode=2     bind-address=0.0.0.0    datadir=/var/lib/mysql  innodb_buffer_pool_size = 300MB innodb_large_prefix=1 innodb_file_format=Barracuda  transaction-isolation = READ-COMMITTED  wsrep_on=ON   wsrep_provider=/usr/lib64/galera/libgalera_smm.so            wsrep_slave_threads = 16          wsrep_max_ws_rows=131072     wsrep_max_ws_size=1073741824     wsrep_convert_LOCK_to_trx=0     wsrep_causal_reads=OFF wsrep_sst_method=xtrabackup-v2


How many triangles are formed by $n$ chords of a circle?

This is a homework problem I have to solve, and I think I might be misunderstanding it. I'm translating it from Polish word for word.     $n$ points are placed on a circle, and all the chords whose endpoints they are are drawn. We assume that no three chords intersect at one point.      a) How many parts do the chords dissect the disk?      b) How many triangles are formed whose sides are the chords or their fragments?   I think the answer to a) is $2^n$. But I couldn't find a way to approach b), so I calculated the values for small $n$ and asked OEIS about them. I got . And it appears that there is no known formula for all $n$.  says that      $\text{triangles}(n) = P(n) - T(n)$      where $P(n)$ is the number of triangles for a convex n-gon in general   position. This means there are no three diagonal through one point   (except on the boundary). (There are no degenarate corners.)   This number is easy to calculate as:      $$P(n) = {n\choose 3} + 4{n\choose 4} + 5{n\choose5} + {n\choose6}        = {n(n-1)(n-2)(n^3 + 18 n^2 - 43 n + 60)\over720}$$      The four terms count the triangles in the following manner [CoE76]:      $n\choose3$: Number of trianges with 3 corners at the border.      $4{n\choose4}$: Number of trianges with 2 corners at the border.      $5{n\choose5}$: Number of trianges with 1 corners at the border.      $n\choose6$: Number of trianges with 0 corners at the border.      $T(n)$ is the number of triple-crossings (this is the number of   triples of diagonals which are concurrent) of the regular $n$-gon.   It turns out that such concurrences cannot occur for n odd, and,   except for obvious cases, can only occur for $n$ divisible by $6$.   Among other interesting results, Bol [Bol36] finds values of n   for which $4$, $5$, $6$, and $7$ diagonals are concurrent and shows that   these are the only possibilities (with the center for exception).      The function $T(n)$ for $n$ not divisible by $6$ is:      $$T(n) = {1\over8}n(n-2)(n-7)[2|n] + {3\over4}n[4|n].$$      where $[k|n]$ is defined as $1$ if $k$ is a divisor of $n$ and otherwise $0$.      The intersection points need not lie an any of lines of symmetry of   the $2m$-gon, e. g. for $n=16$ the triple intersection of $(0,7),(1,12),(2,14)$.   If I understand the text correctly, it doesn't give a general formula for $T(n)$. Also I've found a statement somewhere else that some mathematician wasn't able to give a general formula solving this problem. I haven't found a statement that it is still an open problem, but it looks like it to me.   So am I just misunderstanding the problem, or misunderstanding what I've found on the web, or maybe it is indeed a very hard problem? It's the beginning of the semester, our first homework, and it really scares me.


Can bowler bowl with two hands (left & right) in international cricket

Recently I've seen in domestic match there was one bowler (spinner) who used his both hands while delivering the ball?  I've doubt can it be possible in International Cricket.  Does ICC has any rule about this?


is $\frac{0}{0}$ indeterminate or undefined?

I know in calculus the form $\frac{0}{0}$ is indeterminate.but if it is not calculus is it still indeterminate or undefined in the real number field?   P.S. I know that $\frac{1}{0}$ is undefined whether it is calculus or normal arithmetic in the real number system. but in the projectively extensive real number system, $\frac{1}{0}=\infty$ but in this system what would be $\frac{0}{0}$ it becomes $0*\infty$ also an indeterminate form. in that system the problem $\frac{1}{0}$ is solved but $\frac{0}{0}$ remains.    P.P.S some answers in the question which has been identified as a duplicate of my Q state the $\frac{0}{0}$ is indeterminate. but in Wikipedia page(division by zero) states it is undefined. and that question was asked not to clarify this ambiguity(indeterminate or undefined) and there is no clear answer to my problem.


Why do we say "rise in demand" instead of "rise in the demand"? Is this logic also applicable for phrases such as "increase in adoption" and "increase in demand"? Please assist. Are these idioms??


I'm a runner (cross country) and I'm always amazed at how fast Olympic sprinters are. There's a lot of hype about those in the 100-meter dash being the fastest in the world, and we're constantly seeing the 100-meter time dropping. But is there a limit? How fast can human being, propelled only by its own energy (i.e. without any external assistance) run?


What is the difference between GDDR3 and DDR3?

I am trying to buy a laptop, and I have seen in many place that they show GDDR3 and sometimes  DDR3. What is the difference between them?  afaik DDR3 is a type of RAM used for system memory, while GDDR3 is a type of RAM used for graphics cards. So does "G" only stand for Graphics or does it have another particular meaning?


grep might not be the solution to what I need. I'm trying to grab the MB/s info from this command dd if=/dev/zero of=tempfile bs=1M count=1024 which returns the following information  1024+0 records in 1024+0 records out xamount bytes(1.1GB) copied, 11.234 s, 30.5 MB/s  what I tried was dd if=/dev/zero of=tempfile bs=1M count=1024|grep -oP '.....MB/s but I'm fairly new to the grep command and I'm sure I'm doing it wrong. also this is on centOS


USB Connection Not Working After Recent AT&T Update on Galaxy S3

I found I failed to transfer pics in galaxy to my computer using USB connection after my recent AT&T update. I chose settings->network->more network. And there is an option to tethering via USB and it did prompt with a connecting sound. However, my Samsung device displays as unrecognized device and there is no extra drive popping in my computer. Does any one may know the solution to this?


Why does my pilot light go out continuously?

My furnace pilot light keeps going out.  The furnace will come on and heat up to the degree set on my thermostat, then the pilot goes out and the furnace will not come back on. Could the thermostat be bad and cause the pilot light to go out? Is there anyway for me to check the problem myself?


Unbiasedness of Bayesian Posterior Mean Under Bayesian and Frequentist Models

This is an extension to  previous question, and is related to exercise 4.7 from .  When is the Bayesian posterior mean $m(y) \equiv E[\theta \mid y]$ unbiased for $\theta$, considering theta either as a random variable (Bayesian perspective) or fixed (Frequentist perspective)?


ArcMap's base map with imagery collection date

How can I determine the collection date for ArcMap's base map with imagery? I'm using ArcMap 10.3.1


Geological/Geographical term for the point where different waters meet/conflux?

If you would like to describe a place where two different waters meet together and form a new stream, what word would you choose? I looked it up online and found word "confluence" can be the choice but I got the feeling that it is  describing about the phenomenon of the conflux rather than the geographical feature of the stream.  That being said, I don't think saying like     XXXX stream is a water confluence       or      XXXX confluence(conflux) is named because it is where two different water bodies meet   will successfully describe what I intend.  Thank you!


Closure of topology sine $Y = \lbrace (x,\sin(\frac{1}{x})) : x > 0 \rbrace $

Given the subspace $Y = \lbrace (x,\sin(\frac{1}{x})) : x > 0 \rbrace \subset \mathbb{R}^2$, I know that $Y$ is connected being the image of a connected of $\mathbb{R}$ (i.e. $(0,+\infty)$.), through a continuous function. I know also that that the closure of a connected is connected, so $\overline{Y}$ is connected, but I'd like to prove that $\overline{Y} = Y \cup \lbrace (0,t) : \lvert t \rvert \leq 1 \rbrace$ Are there any simple method to prove it ?


Is there a way we can check and refer the source codes which execute the commands like "CayleyGraph()", "SemidirectProduct()" which are used for computations in GAP software?


Is $(xy-1)$ a maximal ideal in $\mathbb C[x,y]$?

I learnd that the maximal ideals in $\mathbb C[x,y]$ have the form $(x-z_1, y-z_2)$ by the Nullstellensatz. But if we set $I=(xy-1)$ then $\mathbb C[x,y]/I$ is isomorphic to $\mathbb C[x,1/x]$ which is in my opinion a field, thus $(xy-1)$ is maximal. Where did I make a mistake?


Inequality problem involving square roots

Show that, if $a$ and $h$ are positive numbers, $h < a^2$, then $$\sqrt{a^2 + h}-a < \frac{h}{2a} < a - \sqrt{a^2 - h}$$  I've been working on this problem for about 2 hours now, but I've made no progress. I'm not looking for an answer, but I just need some help to get me started since we didn't practice inequalities this complex in highschool. Thanks.   All I can tell is that we're supposed to take the square root of an expression at some point since one inequality ( h < a^2 ) becomes two.   Edit : Thank you guys for the replies, but I'd appreciate only hints in the future (like Robert Israel) so that I can learn. Regardless, I found a different way to do it, so it's cool :)


Flattening the intersection of overlapping spheres

as everybody know, when you put two spheres close to each other  they intersect other like this :     How do I flatten the spheres at the region where they intersect each, I tried to illustrate this with a quickdraw :  I don't know if it's possible with physics like soft body or collision. does anyone know how to get this result,  i need this for a still image not for animation.   I'm more looking for something like this:


iPhone shows apple logo and iPhone is not restored gives unknown error 2001

my iPhone5 is dropped from my hand when i put from floor than it shows continuously apple logo i attached iPhone with itunes and try to restore after download whole software it gives error The iPhone "iPhone" could not be restored. An unknown error occurred (2001).  please provide me any solution. i'm so much worry about this. thanks in advance


For example:     The building is accurate to its schematics   Is this invalid use of the word "accurate"?


Python Scoring System Referenced Before Assignment

I have tried to make my scoring system for my quiz work for days now with no avail. I have tried 'global', +=, score = score + 1, and so on and I am always getting pretty much the same error. "Local Variable "score" referenced before assignment", however I have put 'score = 0' at the top, also noting that the question is in a 'def' function. I tried some tests in a separate document and when I remove the function from the code, it seemed to add / subtract points fine. I would like to have functions within my code to be able to return to the beginning of the question when a incorrect answer is inputted. Thanks.  Whole Code:   import time score = 0  def question1():    question_1 = input("1.\n2.\n3.\n4.\n")    if question_1 == "3":     time.sleep(0.5)     print("Correct!")     score += 1     print ("Your now have a score of ",s,"!")    else:     print("Incorrect..")     time.sleep(0.5)     score -= 1     print ("Your now have a score of ",s,"!")     time.sleep(0.5)     print("Try Again")     time.sleep(0.5)     return question1() question1()


I have a list of elements created dinamically. Each item has an ID. I didn't find how to get the id of each element when it is clicked.  Nothing is working out... :(


Problem with GRUB with Linux on USB and Windows 10 on SSD

I installed Ubuntu on usb stick (not live, like here: ).  But when installer asked me if I really want to install without swap partition I didn't know what to do and I partitioned my Sandisk ultra fit: swap 5gb (somewhere I read that if I set swap partition larger than amount of RAM I'll be able to hibernate - but I can't), / 15gb and /home 10gb. It agree that it might not have been the most clever solution on the world.   However, my problem is: When I run windows or Ubuntu, shut down computer, and turn it on again there is a grub program, which seems to not be able to see any OS:    What is interesting, I just have to enter the bios (don't even have to do anything except save & exit) and after restart there is normal grub purple screen with boot options, from which I can start Ubuntu and Windows. But when I turn it off, the problem recurs. Moreover, in bios, in boot options, I can see: my ssd, and TWO positions with Sandisk ultra fit (the same) - even if I delete one of Sandisks, the next time I enter BIOS there are all three options again.  Can anyone tell me what's going on? I can live with this, but it's boring to enter bios every time when turning my machine (ASUS us303, if it helps) on. Also, I'll be grateful if you could advise me how to partition my USB stick in case I need re-installation.


Can you still become a vampire lord if you have killed Harkon and cured Serana?

Can you still become a vampire lord if you have killed Harkon and cured Serana on Xbox 360? I tried to talk to Serana before I cured her but the option did not come up.


Jquery Button events and form sends not working on setinterval

I have a table and I have buttons in every row. if I disable setinterval everything works fine but when I start setinterval I only load page any buttons not working.  <script src="folder/js/jquery-2.1.4.min.js"></script> <script>  $(document).ready(function() {  var refreshId = setInterval(function() {     $("#refresh").load(location.href + ' #refresh');     }, 1000);     $("#acceptOrderButton").click(function(event){     clearInterval(refreshId);      alert ("in");  });   });   If I disable Set interval and clear interval I see the alert on button click. What can be the problem?  My Button is inside div. So the problem is it. Is there nay way to do it?  <body>  <table id="refresh">     <tr>         <td>             <button id="acceptOrderButton">click</button>            </td>     </tr> </table> </body>


In python, how do I make a class a generator?

I'm working with the varnish API in varnish 4.  The way it produces log entries is by Dispatch'ing against it, and passing in a callback.  Simple version:  class vlog(object):     def __init__(self):         self.body = []     def callback(self, vap, cbd, priv):         self.body.append(cbd)     def main(self):         self.vlog = varnishapi.VarnishLog(sopath="libvarnishapi.so")         while True:             ret = self.vlog.Dispatch(self.callback)             if ret == 0:                 time.sleep(0.1)   I need to do several more things in self.callback to aggregate the data properly, but whatever.  My REAL question is this:  How can I turn the above class into a generator?  My ideal usage would be something like this:      vlog_inst = vlog()     for log_aggregate in vlog_inst:         pass   Simply putting a 'yield' statement in the callback function never triggers iteration.  (surprising to me, adding the yield statement also causes all of my print statements to produce no output as well... I'm obviously missing something.)


How to redirect non-logged in users to a specific page?

How to redirect non-logged users requesting for a specific page/URL to another page/URL and display a message like "for members only".  I know its quite easy to code using !is_user_logged_in() function but i don't know how to code it because i am a newbie to WordPress.  Care to tell me the file to put the code also.


A topological space is locally compact then here is an open base at each point has all of its set with compact closure

A topological space is locally compact then there is an open base at each point has all of its set with compact closure, how can i prove it?  It seems very meaningful when the topological space is metrizable and the topology is the topology induced by the metric, but i could not prove it for general topological spaces.  I am not familiarized with Hausdorff spaces.  What i tried for now is starting from the definition of locally compact as the topological space whose ever point has a neighbourhood with compact closure. I picked (for each point) this neighbourhood, and created a class with all open sets contained in that neighbourhood, then i thought that this class may be the open base at the analized point whose all sets have compact closure, but i could not prove that this class is an open base at point, have someone an idea? Or other path to prove it, or yet is this claiming false?


Let $g(x)$ be continuous for all $x$ and let $g(a+b) = g(a) + g(b)$ for all $a$,$b$...

Show $g(x) = g(1) \cdot x$ for $x = c, \frac{1}{c}$ and $\frac{d}{c}$, where $c, d \in \mathbb{Z}, c \neq 0$.     For $x=c$, I was thinking of doing an induction proof, as $g(c) = g(\frac{c}{2}) + g(\frac{c}{2})$. However, I'm not sure how to handle the latter two cases.


I'm confused about the following examples, and I'm pretty sure I've seen both of them in books and white papers.   What I have to do is find her. What I have to do is to find her. What I would like to do is to buy it. What I would like to do is buy it   Can anyone please tell me which one is correct?  Many thanks


I’m trying to add c wire to furnace to run a WiFi thermostat but don’t know where to hook up c wire to get power to turn on thermostat i have 2 extra wires just don’t know where to put one them to get power


I have two tables in my database namely tutors and students with the following structure:  tutors table +------------+--------------------+---------------------+ |tutor_id    |tutor_avail_credits |entry_time           | +------------+--------------------+---------------------+ |    20      |      300           | 2017-01-22 11:53:10 | +------------+--------------------+---------------------+ |    13      |      200           | 2017-01-24 13:58:45 | +------------+--------------------+---------------------+   students table +------------+--------------------+---------------------+ |student_id    |student_credits   |entry_time           | +------------+--------------------+---------------------+ |    20      |      50            | 2017-01-24 12:23:10 | +------------+--------------------+---------------------+ |    13      |      100           | 2017-01-24 15:58:45 | +------------+--------------------+---------------------+   I have a PHP script that allow students to reserve a tutor for a tutoring session that will run for minutes equivalent to student's credits. The way I had intended it to work was that, I run a query to fetch rows for the top most tutor(earliest since the list is sorted according to time)    $query = "SELECT * FROM tutors               WHERE (tutor_avail_credits > 0 )             ORDER BY entry_time ASC LIMIT 1 ";   If a student submits a form to reserve the top most tutor, his/her credits should be subtracted from the tutors credits until the tutor is fully reserved. Each time a reservation occurs tutor_avail_credits field should be updated until it's 0. So I have this code.         <?php           //Check if reserve button press         if(isset($_POST['reserve'])){             //Some code here.........          if($student_credits < $tutor_avail_credits){             $tutor_avail_credits = $tutor_avail_credits - $student_credits;             //Update table field.              $update = "UPDATE tutors                         SET  tutors_avail_credits = '$tutors_avail_credits'                        WHERE tutor_id = '$tutor_id'"             }            //Code continues.....            ?>   Now the problem is that the field tutor_avail_credits will be accessed by multiple users at the same time, won't this cause some problems? if so, is it possible for me to have additional column in tutors table where I can set a flag after running a SELECT query so that it will be used as a condition allowing other users to select tutors which are currently not selected.Here is the query.   $query = "SELECT * FROM tutors               WHERE (tutor_avail_credits > 0 AND status ='available')             ORDER BY entry_time ASC ";   Please I am a beginner point me in the right direction.


A matrix $M$ that commutes with any matrix is of the form $M=\alpha I$

I feel like this is probably a simple proof but I can't quite come up with it in an elegant way nor could I find it here.  Prove that if a matrix $M$ commutes with any matrix then $M$ is of the form $M=\alpha I$.  Proving the contrapositive seems like the natural way to go where we can logically transform $\lnot \forall A(MA = AM)$ into $\exists A (MA \neq AM)$ but assuming that $M \neq \alpha I$ immediately becomes messy. Is there a nice way out of this or is it inevitably going to get messy?


json_encode() doesn't display arabic characters in good way

i have problem with Arabic characters when i do json_encode() it always return ????, in the database all the fields and database is utf8  my code:  $query   = mysql_query("SELECT * FROM `Names`");  if (!$query) { $message  = 'Invalid query: ' . mysql_error() . "\n"; die($message); }else {     while ($row = mysql_fetch_assoc($query))      {      $result[] = array(         'Mid' => $row['Mid'],          'Uid' => $row['Uid'],          'Cid' => $row['Cid'],          'Name' => $row['Name'],         'city' => $row['city'],         'status' => $row['status'],         'Mobile' => $row['Mobile'],         'Phone' => $row['Phone'],         'Email' => $row['Email']);     }       header('Content-Type: application/json; charset=utf-8');       echo json_encode($result); }   the result look like:  [{"Mid":"17","Uid":"1","Cid":"8","Name":"???? ?? ??????? ?? ???","city":"?????",   please help me


301 redirect all child pages to parent directory using .htaccess

I need to 301 redirect all child pages of a specific parent directory on my website.   i.e. redirect www.example/com/parent/child and www.example.com/parent/another-child etc. to www.example.com/parent  Is this achievable using the .htaccess file?


Is gravity weak negative electric charge?

This could be true since the both have infinite range and other common properties. They both have fields.


Yesterday afternoon I arrived Delhi. So if I want to Inform my friends which word should I use  I am At Delhi or I am in delhi


How to increase space between the bottom border of a boxed figure and its caption?

I am trying to generate a space (6pt) between the boxed figure and its caption. Since I am using tikz code \includegraphics did not work. Also I tried \setlength{\abovecaptionskip}{6pt}, \captionsetup[figure]{skip=6pt}. However they did not work. How to handle this problem?    \documentclass[a4paper,12pt]{article} \usepackage[margin=10pt,font=small,justification=centering]{caption} \usepackage{tikz} \usepackage{floatrow} \usepackage{float,lipsum} \floatstyle{boxed} \restylefloat{figure} \usepackage{wrapfig} \usepackage{caption} \usepackage{subcaption} \usepackage{amsmath}  \begin{document} \begin{figure}[ht] \begin{center} \begin{tikzpicture}[thick,scale=1] \filldraw[black] (0,0) circle (2pt) (1,1) circle (2pt) (1,-1) circle (2pt) (3,1) circle (2pt) (3,-1) circle (2pt) (4,0) circle (2pt); \draw (0,0) -- (1,1) -- (1,-1) -- (0,0); \draw (1,1) -- (3,1) -- (4,0) -- (3,-1) -- (3,1); \draw (3,-1) -- (1,-1)--(1,1); \draw (3,1)-- (3,-1); \draw (4,0) -- (0,0); \node[above] at (1,1) {$v_1$}; \node[left] at (0,0) {$v_0$}; \node[below] at (1,-1) {$v_5$}; \node[below] at (3,-1) {$v_4$}; \node[right] at (4,0) {$v_3$}; \node[above] at (3,1) {$v_2$}; \end{tikzpicture} \caption{$G$.} \label{factorex} \end{center}  \end{figure}   \end{document}


Finding $\lim_{n\rightarrow \infty} \sqrt[n]{\binom{\alpha n}{n}}$

I've seen in my book a solution to the case $\alpha=2$ by showing $a_n=\binom{2 n}{n}=\prod_{i=1}^n\frac{(2i-1)(2i)}{i^2}(=b_i)$, so $\lim \sqrt[n]{a_n}=\lim b_n=4$  for $\alpha=3$, by denoting $a_n=\binom{3n}{n}$ they show $\frac{a_{n+1}}{a_n}=\frac{(3n+1)(3n+2)(3n+2)}{(n+1)(2n+1)(2n+2)}\rightarrow \frac{27}{4}$ which is also the limit of $\sqrt[n]{a_n}$ (there was a question before that proved  $\lim_{n \rightarrow \infty} \sqrt[n]{a_n} = \lim_{n \rightarrow \infty} \frac{a_{n+1}}{a_n}$ prior).  Is there some generalization of this for all $\alpha\in\mathbb{N}$?


When i'm creating blog subsite i have app named 'Posts'. Is there any way to use this app in team site?  That's what i mean:


Hardware requirement for video serving to 1000 concurrent users

Can someone help us, we are looking to roll out a video on demand platform to provide internal staff the ability to view content.   we will need to stream to 1000 users, the video files will be 720p videos of max size typical 250MB. they will all be streaming various aspects including pre-encoded & possibly encrypted videos (with codecs supplied to end users)     we have been recommended the following hardware   Intel Xeon 3.6ghz 4 core 64GB 6x 1.2TB SAS disks & 2x 800GB SSD write intensive 4x 1g NIC’s  but are trying to find a way to calculate the concurrent user load this server would be able to provide and any recommendations to meet our requirements.


When do we not use definite article, "the"?

I have a question. Could you please explain why “the” is not used in the parts that I have indicated in bold? Why is "the" missing?     Little is known about the lives of early human beings. What we do know has been gathered through the study of ancient caves that scientists called archeologists believe early humans probably lived in.   The evidence suggests that the first human beings lived in caves along the southern coast of Africa. This region provided ample supplies of food as well as a warm climate.   The text above is from


$G$ group, $H \trianglelefteq G$, $\vert H \vert$ prime, then $H \leq Z(G)$

Let $G$ be a finite group. Let $H \trianglelefteq G$, with $\vert H \vert = p$, a prime, where $p$ is the smallest prime dividing $\vert G \vert$. Prove that $H \leq Z(G)$. (Hint: If $a \in H$, by normality, its conjugacy class lies inside $H$.)   My approach so far:  Let $a \in H$. Then $C(a) = \{gag^{-1} : g \in G\} \subseteq H$. Now, since $\vert H \vert$ is prime, it follows that $H$ is cyclic and moreover $H$ is abelian, hence $C_H(a) = H$ for all $a \in H$ and equivalently $[H: C_H(a)] = 1$ for all $a \in H$.  Try to show $\vert C(a) \vert = [G:C_G(a)] = [H:C_H(a)] = 1$.  So, since $\vert C(a) \vert = 1$ for all $a \in H$, we have $C(a) = \{a\}$ for all $a \in H$ and equivalently $a \in Z(G)$ for all $a \in H$, so we can say $H \subseteq Z(G)$ and moreover $H \leq Z(G)$.  My main question is, how to show $[G:C_G(a)] = [H:C_H(a)]$. But also, I haven't used the fact that $p$ is the smallest prime dividing $\vert G \vert$, so is my reasoning wrong anywhere?


I was assigned by the lecturer to conduct a user experience evaluation on an existing website. Then in the question, he asked us how you quantify user experience and heuristic that you will be using for your expert review. I thought ux is about feelings and experience? how do you quantify it? Is it correct if I say by doing research such as questionnaire?


Consider the following example of a patch using  and a dummy macro \abc:    \documentclass{article} \usepackage{etoolbox}% http://ctan.org/pkg/etoolbox \newcommand{\abc}[2]{#1\ #2}% Magic macro \begin{document} \abc{A}{B}  % \patchcmd{<cmd>}{<search>}{<replace>}{<success>}{<failure>} \patchcmd{\abc}{#1}{#2}{}{}% \abc{A}{B} \end{document}   If I want to maintain good programming practice, I'm encouraged to put \patchcmd in the document preamble (separating structure from content) and only trigger it with a different macro, say \patchabc:  \documentclass{article} \usepackage{etoolbox}% http://ctan.org/pkg/etoolbox \newcommand{\abc}[2]{#1\ #2}% Magic macro \newcommand{\patchabc}{%   % \patchcmd{<cmd>}{<search>}{<replace>}{<success>}{<failure>}   \patchcmd{\abc}{#1}{#2}{}{}% } \begin{document} \abc{A}{B}  \patchabc% Patch \abc \abc{A}{B} \end{document}   However, the above does not work since #1 and #2 inside \patchabc is assumed to reference its arguments while \patchabc has none. How can I write a macro that acts like a switch (and is cleaner in terms of the programming) that patches another macro's use of its own arguments?


How to use dynamic keys in Chrome local storage get and set?

If I do something like this in my Chrome extension it works fine:  chrome.storage.local.set({"Foo1": dataValue});   And this is fine:  chrome.storage.local.get("Foo1", callback);   But when I try to abstract these info functions so that I can use different key names for different situations:  function saveLocalData(dataKey, dataValue){     chrome.storage.local.set({dataKey: dataValue}); } saveLocalData("Foo1", "hello foo");   ...and then this:  function getLocalData(dataKey, callback){     chrome.storage.local.get(dataKey, callback); } getLocalData(dataKey, myCallbackFunction);   ...both the save and the get seem successful, but upon retrieval I only seem to have an empty object. I have stepped through my code in chrome dev tools and examined the [Object] that comes back -- it's not null -- but it seems to be empty and useless, and if it has my data somewhere down in the bowels, I can't seem to find it.  I even tried this, but with no better results:  function getLocalData(dataKey, callback){     dataKey = "\"" + dataKey + "\"";     chrome.storage.local.get(dataKey, callback); }  function saveLocalData(dataKey, dataValue){     dataKey = "\"" + dataKey + "\"";     chrome.storage.local.set({dataKey: dataValue}); }   There must be some way to abstract local storage getters and setters into a function so that I can pass in a key name and a value (to save), then later retrieve the desired value by passing in the correct key name. Cookies work this way but local storage has some kind of voodoo that I'm not understanding. I am only using callback functions for getLocalData() because I don't need callbacks in the setter. My callback is working - the callback function is entered and I get that seemingly empty [Object] -- it is not just null.  Please help, and thanks in advance.


How can I set a "global" bash variable (cache the variable in parent shell)?

I have a script that has:  global_npm_modules_path="$(npm root -g)";   this npm command is slow, and I am looking to speed up this script. One thing I could do is "cache" the result of the npm command, something like this:  export global_npm_modules_path=${global_npm_modules_path:-"$(npm root -g)"}   but my question is - how can I set global_npm_modules_path so that it's held in store by the parent shell / parent process?  The problem is the export command will only be relevant for this shell and its children.


Finding the closed form of $\sum_{i = 1}^{n - 1}i \cdot 2^{-i}$

I'm currently working on an assignment where I have to find the average case runtime of an algorithm. I've found the formula for it, which is $\sum_{i = 1}^{n - 1}\frac{1}{2}^i \cdot 2i$ which I've simplified to $f(n) = 2 \cdot \sum_{i = 1}^{n - 1}i \cdot 2^{-i}$. I'm now trying to find the closed form of the sum in the formula but I'm having a lot of trouble with it. What I do know, is that $\lim_{n \to \infty}f(n) = 4$ but I'm not sure what to do with this information. Thanks in advance for any help!


Path connectedness of the set $\{(x,y):(x+1)^{2}+y^{2}\leq 1\}\cup\{(x,y):y=x\sin(\frac{1}{x}),x>0\}$

Let $A$ be the following subset of $\mathbb{R}^{2}$:$$A=\{(x,y):(x+1)^{2}+y^{2}\leq 1\}\cup\{(x,y):y=x\sin(\frac{1}{x}),x>0\}$$ Then  $1.$ $A$ is connected.  $2.$ $A$ is compact.  $3.$ $A$ is path connected.  $4.$ $A$ is bounded.  It is clear that $A$ is unbounded as the graph of $x\sin(\frac{1}{x})$, so option $2$nd and $4$th are not correct. Again $A$ is connected by using the fact that closure of connected set is connected. But i am confused about path connectedness of $A$. Please help me about path connectedness of $A.$ Thanking you.


I have ubuntu 12.04.2 along with windows 7. I absolutely liked it! But I now want to uninstall this version, reinstall windows 7 and again install ubuntu. How do I remove ubuntu 12 from my system? I have a boot usb from which I installed the software. The control panel shows ubuntu installed on the system. I tried removing it from the add/remove programs. But it did not work! How do I go about it.?


At what speed will objects hit a singularity?

I have read in numerous places  that an object in free fall into a black hole will be travelling the speed of light when it passes the event horizon.  How is it possible to go this fast?  Does it continue accelerating, faster than light until it is crushed by the singularity?


numpy - return first index of element in array

What's the fastest way of returning the index of the FIRST match between a variable and an element within an ndarray? I see numpy.where used a lot, but that returns all indices.  match = 5000 zArray = np.array([[0,1200,200],[1320,24,5000],[5000,234,5230]])  >array([[   0, 1200,  200],    [1320,   24, 5000],    [5000,  234, 5230]])  numpy.where(zArray==match) >(array([1, 2], dtype=int64), array([2, 0], dtype=int64))   I'd like the first index returned, i.e. just [1,2]. but numpy.where returns both [1,2] and [2,0]


I am trying to add a repository in Debian 6.0.8  sudo cat /etc/debian_version 6.0.8  sudo apt-get install software-properties-common E: Unable to locate package software-properties-common  sudo apt-get install python-software-properties 0 upgraded, 0 newly installed, 0 to remove and 99 not upgraded.  sudo add-apt-repository ppa:kakrueger/openstreetmap sudo: add-apt-repository: command not found   Is any other alternative to install software from that repository?


I have no maintenance plans yet I see indexes being created in the background (low spid). I have no idea what indexes are being created or why. Using Standard SQL Server 2017 - a VM on Azure with SQL Installed.    I checked and did not see anywhere with automatic index management.  You can configure backups, etc. but I cannot find a spot for indexing.  I tried EXEC sp_WhoIsActive @show_system_spids = 1; and got this result:  (542701ms)RESOURCE_SEMAPHORE   I think what is happening is I have a "messed up index" and the system is trying to fix it.  I cannot drop the index whatsoever or rebuild it.  At least that is my guess.


Graph Theory: Prove this group of people can be divided into two groups

In a party each person has at most 3 friends. Prove that people in the   party can be divided into two groups, such that each person has at   most one friend in his group.   Any idea how to start the proof?


Idiom for doing anything to get what you want

I'm looking for an idiom which describes a person who does everything to get what he wants even by being dishonest.


Not able to install CURL on Ubuntu 12.04

When I am trying to install the following error is coming  sudo apt-get install php5-curl Reading package lists... Done Building dependency tree        Reading state information... Done You might want to run 'apt-get -f install' to correct these: The following packages have unmet dependencies:  gedit : Breaks: gedit-plugins (< 2.91) but 2.30.0-0ubuntu1 is to be installed  php5-curl : Depends: php5-common (= 5.3.10-1ubuntu3.11) but 5.3.10-1ubuntu3.10 is to be installed E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).   Can anyone please highlight the issue and give some solution?


Weight from field option not showing all fields from attribute table in heatmap algorithm in QGIS 3.18.1

I'm trying to create a heatmap on a shapefile of numerous points based on a single field in their attribute table. The header of the attribute table is this:  ... and I want to make a heatmap weighted on the "frp" field from the attribute table. However, in the Heatmap (Kernel Density Estimation) settings, I cannot see the "frp" field - only the "longitude" and "latitude" values appear:  What could be wrong here?


How to add missing tag to a Stack Exchange question

I saw a question on Stack Overflow and it's about Java. The post had a number of tags but not the important one, so the source code of that question looks as ugly as plaintext because the syntax highlighting was not working.  I tried to add java to the tags of that question, but I got an error  Your edit summary must be at least 10 characters   Can't we add missed tags for a question without adding anything to the body?


Can I visit Schengen countries on a Type-D Schengen Visa?

I’m going to Germany for a semester exchange and I have a long-stay visa from Germany. Can I travel to the other Schengen states during this period with this visa or do I have to apply for a separate short stay Schengen visa?  My visa is German national visa type D. It is for a duration of 4 months, i.e., longer than 90 days. It says on the visa that the long stay visa is valid in Deutschland, which is different from my earlier visa, which I had when I visited Germany earlier; that one was a short stay visa and said it was valid in Schengen Staten.  Perhaps my current visa means that I can stay in Germany for a period of longer that 90 days can visit the other Schengen states if I don’t exceed the 90 day period.


Conjugation of a group: what is it and where does $g⋅a = gag^{-1}$ play into it?

So this is a pretty general question, and I'm not even sure what it is I should be asking. Basically my abstract algebra textbook does not clearly define conjugations and just sort of throws out this: $$g⋅a = gag^{-1}$$ I don't know what this comes from or what it is saying, but from my trying to figure this out, it seems like it comes up a lot, and I just can't make sense of it. I keep trying to visualize everything group-related as symmetric permutations, but I imagine this is very limited, especially when considering a group acting on itself. (How does that work?) Are there other ways of visualizing what this is trying to say? Let me know if providing the hw question that led to this confusion is worth commenting


I am curious why a signed integer value was used to hold Unix time. It clearly would have made significantly more sense to use an unsigned integer as time can't go backwards, so having a negative value for time is, well, impossible. However, on January 19, 2038 Unix time will overflow and it will be the end of time as many of us know it. We will go from 2,147,483,647 to -2,147,483,648... Not good.  So, why was a signed integer used and how hard would it be to implement a fix for this when the end of time does come near?


How to change the login procedure on Ubuntu14.04

My system:  Ubuntu14.04  Linux version 4.4.0-144-generic (buildd@lgw01-amd64-023) (gcc version 4.8.4 )  I try to change the login procedure to realize a function that a NULL string and my password can both login in Ubuntu.Some web info suggest me download util-linux-2.13-pre7.tar.bz2 and remake the login.c.But when I make the login.c(in util-linux-2.13-pre7/login-utils/),there is a error:  /usr/include/time.h:192:15: note: expected ‘time_t *’ but argument is of type ‘int32_t *’  extern time_t time (time_t *__timer) __THROW;  I have google this error and knew that is a 32bit/64bit linux bug.So I doubt that the login.c in util-linux-2.13-pre7.tar.bz2 is not suitable for Ubuntu14.04.   So my question are :   1.If the util-linux-2.13-pre7.tar.bz2 is not suitable for Ubuntu14.04,which version is suitable for Ubuntu14.04.   2.Could I change the login procedure through remake login.c?


Proving Finiteness of Group from Presentation

Given the group $G = \langle a, b, c : a^2 = b^3 = c^5 = abc\rangle$, I want to show that $H = G / \langle abc\rangle$ is a finite group.   I tried to find a canonical form for elements of $H$. That didn't work. Then I tried to find a finite normal subgroup of $H$ of finite index, but this didn't work either. I'd be grateful if someone could show me a correct method to solve this problem.


How can I split a string maintaining the punctuation? (Python)

How can I split a string in python taking into account the punctuation in the result?  The following code:  s = "Hello, my name is Robert." s_splitted = s.split()   will give as output:  ["Hello,","my","name","is","Robert."]   How can I obtain the following result?  ["Hello",",","my","name","is","Robert","."]


What does "No apport report written because MaxReports is reached already" mean?

When installing a Linux kernel image package, I got, amongst other errors:     No apport report written because MaxReports is reached already   Where  can I delete old reports so that Apport can resume doing its bug reporting magic again?


Upgrade SQL Server database Using Compatibility Level

I've made a backup of a SQL Server database running on SQL Server 2008. I've restored that backup into a SQL Server 2012 instance. I've set the compatibility level on the restored instance to SQL Server 2012 (110).   What does this do to the database?   Does it, for example,    cause stored procedures to be examined for incompatibilities cause any updates to all of the data pages in the database Cause updates to to datapages as the are accessed in the future Cause errors in the future if stored procedures or views are executed that use incompatible syntax   Where in books on line, or else where, can I find more detail?


Apache - can't access subdirectories but can access document root

As per title - I have a server running wherein I can access index.html placed in the document root (/var/www/html), but not any subdirectories within the document root.  Permissions on root index:  $ namei -l /var/www/html/index.html f: /var/www/html/index.html dr-xr-xr-x root   root   / drwxr-xr-x root   root   var drwxr-xr-x root   apache www drwxr-x--- myuser apache html -rwxr-x--- myuser apache index.html   Permissions on subdirectory index:  $ namei -l /var/www/html/foo/bar/index.html           f: /var/www/html/foo/bar/index.html dr-xr-xr-x root   root   / drwxr-xr-x root   root   var drwxr-xr-x root   apache www drwxr-x--- myuser apache html drwxr-x--- myuser apache foo drwxr-x--- myuser apache bar -rwxr-x--- myuser apache index.html   Security context info on /var/www/html:  $ ls -Z /var/www/html drwxr-x---. myuser apache unconfined_u:object_r:httpd_sys_content_t:s0 cszg -rwxr-x---. myuser apache unconfined_u:object_r:httpd_sys_content_t:s0 index.html   Security context info on /var/www/html/foo/bar:  $ ls -Z /var/www/html/foo/bar                         -rwxr-x---. myuser apache unconfined_u:object_r:user_home_t:s0 3rdpartylicenses.txt -rwxr-x---. myuser apache unconfined_u:object_r:user_home_t:s0 es2015-polyfills.24633e0ae24ffe204041.js -rwxr-x---. myuser apache unconfined_u:object_r:user_home_t:s0 favicon.ico -rwxr-x---. myuser apache unconfined_u:object_r:user_home_t:s0 index.html -rwxr-x---. myuser apache unconfined_u:object_r:user_home_t:s0 main.38de9b2b74351642ba79.js -rwxr-x---. myuser apache unconfined_u:object_r:user_home_t:s0 pdfjsWorker.382cb0cf8fa9c06b8500.js -rwxr-x---. myuser apache unconfined_u:object_r:user_home_t:s0 polyfills.e1e93dfb20909209aa48.js -rwxr-x---. myuser apache unconfined_u:object_r:user_home_t:s0 runtime.1f744383c7edc51f6732.js -rwxr-x---. myuser apache unconfined_u:object_r:user_home_t:s0 styles.9e51190222492c49b9b3.css   Finally, here's the relevant parts of httpd.conf:  User apache Group apache  DocumentRoot "/var/www/html"  <Directory />     AllowOverride None     DirectoryIndex index.html     Require all denied </Directory> <Directory "/var/www/html">     Options FollowSymLinks     Require all granted </Directory>   The error logs indicate this is a permissions problem (AH00132), but as far as I can see the permissions are exactly the same for the root index and the subdir index?


"helps making", "helps make", "helps to make" - what is the difference?

For the three sentences below:  Good horizontal spacing helps make individual statements more readable.   Good horizontal spacing helps to make individual statements more readable.   Good horizontal spacing helps making individual statements more readable.  Is one of them preferable to the others? If so, please justify. Are any of them incorrect?


C++ determine if a container has ::find()

I have a functor which operates on a container of type U of elements of type T like so  template<typename T, template<typename...> class U> class asserter  { public:     asserter(U<T> &c) : container(c) { };     void operator()(T lhs)      {         CU_ASSERT(container.find(lhs) != container.end());     }; private:     U<T>    &container; };   which I might use as   std::set<std::string> a, c; ... asserter<std::string, std::set> ass(c); for_each(a.begin(), a.end(), ass);   Where we are ignoring std::includes() for the moment.   This works great if the container is one where U::find() is defined. If it's not I'd like to fall back to std::find(). On the other hand I'd rather use U::find() over std::find() if it's available.   In C++11 (or 17 if necessary) can I determine if U::find() is available (possibly restricting to the STL) for U and if so use it, otherwise use std::find()?


How can I install ubuntu on pc using vmware image

I am using win 7. I have been using VMware for a while, I have installed ubuntu in it.  Now is there any way, I can use this ubuntu image (vmdk) to install another OS on my pc parallel to win7  I hope the question is clear.


Prior to posting this question, I have read the post here:   My purpose in asking same questions with different wordings is I don't think many understand the situation. For the final time, here's my predicament.   I have a chess worksheet.   Each worksheet has 4 different group. GroupA, Group B, Group C, and GroupD  Each group has three diagrams.   The worksheet would show in proper order: Group A with three diagrams, Group B with three diagrams, Group C with three diagrams, and Group D with three diagrams in the same orders.   If you compile it, the 1st page of pdf output will show correctly the group with their diagrams. Let's call this Model Worksheet.  Let us suppose I add another 3 diagrams to each group so that each group will now have 6 diagrams.   Using the same foreach loop, here's what I get.   Page 1: (Model Worksheet) Group A, Group B, Group C, Group D  Page 2 output is showing Group A, Group A, Group B, and Group B  Page 3 output is showing Group C, Group C, Group D, and Group D.  What must I do to fix the foreach loop to show same as the Model Worksheet? It has been suggested that I used expl3 to solve the problem. I have no idea on how to implement it.  I am willing to research and learn. Please offer me steps so I can get to the solution.  Thank you for your time.  \documentclass{article} \usepackage{xskak,chessboard} \usepackage[margin=3cm]{geometry} \begin{document}  %**** MODEL WORKSHEET. HAS CORRECT ORDER - 3 IN GROUP A, B, C, AND D ************** %***** FOREACH LOOP WORKS CORRECTLY ***** \foreach \X/\Y in  %******* GROUP A ***************** {GroupA/{3k4/8/2Q5/4K3/8/8/8/8 w - - 0 1, 8/8/2k5/7R/6R1/8/5K2/8 w - - 0 1, 1k6/7R/3K4/8/8/8/8/8 w - - 0 1}, %******* GROUP B ***************** GroupB/{8/8/8/8/8/1k6/7P/4K3 w - - 0 1, 8/8/8/8/4k3/4p3/4K3/8 w - - 0 1, 8/1k6/8/8/1PK5/8/8/8 w - - 0 1}, %************ GROUP C ******************* GroupC/{8/8/8/4p1K1/2k1P3/8/8/8 w - - 0 1, 8/8/8/p7/P7/7k/7P/6K1 w - - 0 1, k7/P1K5/6p1/7p/7P/8/8/8 w - - 0 1}, %************ GROUP D ******************** GroupD/{4BK2/6P1/5k2/8/8/1b6/8/8 w - - 0 1,  8/8/4k3/2p4n/2P1K3/8/7B/8 w - - 0 1, 8/p7/P5p1/1P4P1/5P2/3kb3/8/3K4 w - - 0 1}} {\noindent\tikz{\node[rotate=90,font=\bfseries,align=center,text width=4cm]{\X};} \foreach \Z in \Y {\begin{minipage}[b]{0.35\linewidth} \chessboard[smallboard,setfen=\Z] \end{minipage}}  } %****** WHEN NEW 3 MORE DIAGRAMS ARE ADDED, FOREACH LOOP GETS WRONG. WORKSHEET IS NOT SAME AS MODEL WORKSHEET ***** \foreach \X/\Y in  %******* GROUP A ***************** {GroupA/{3k4/8/2Q5/4K3/8/8/8/8 w - - 0 1, 8/8/2k5/7R/6R1/8/5K2/8 w - - 0 1, 1k6/7R/3K4/8/8/8/8/8 w - - 0 1}, GroupA/{3k4/8/2Q5/4K3/8/8/8/8 w - - 0 1, 8/8/2k5/7R/6R1/8/5K2/8 w - - 0 1, 1k6/7R/3K4/8/8/8/8/8 w - - 0 1}, %******* GROUP B ***************** GroupB/{8/8/8/8/8/1k6/7P/4K3 w - - 0 1, 8/8/8/8/4k3/4p3/4K3/8 w - - 0 1, 8/1k6/8/8/1PK5/8/8/8 w - - 0 1}, GroupB/{8/8/8/8/8/1k6/7P/4K3 w - - 0 1, 8/8/8/8/4k3/4p3/4K3/8 w - - 0 1, 8/1k6/8/8/1PK5/8/8/8 w - - 0 1}, %************ GROUP C ******************* GroupC/{8/8/8/4p1K1/2k1P3/8/8/8 w - - 0 1, 8/8/8/p7/P7/7k/7P/6K1 w - - 0 1, k7/P1K5/6p1/7p/7P/8/8/8 w - - 0 1}, GroupC/{8/8/8/4p1K1/2k1P3/8/8/8 w - - 0 1, 8/8/8/p7/P7/7k/7P/6K1 w - - 0 1, k7/P1K5/6p1/7p/7P/8/8/8 w - - 0 1}, %************ GROUP D ******************** GroupD/{4BK2/6P1/5k2/8/8/1b6/8/8 w - - 0 1, 8/8/4k3/2p4n/2P1K3/8/7B/8 w - - 0 1, 8/p7/P5p1/1P4P1/5P2/3kb3/8/3K4 w - - 0 1}, GroupD/{4BK2/6P1/5k2/8/8/1b6/8/8 w - - 0 1, 8/8/4k3/2p4n/2P1K3/8/7B/8 w - - 0 1, 8/p7/P5p1/1P4P1/5P2/3kb3/8/3K4 w - - 0 1}} {\noindent\tikz{\node[rotate=90,font=\bfseries,align=center,text width=4cm]{\X};} \foreach \Z in \Y {\begin{minipage}[b]{0.35\linewidth} \chessboard[smallboard,setfen=\Z] \end{minipage}} \par } \end{document}


Getting string representation of a variable in Python to use in dict as a key

For example I have 2 variables:  a = 2 + 2 b = 3 + 3   And now I want to construct a dictionary where keys are variable names, that is “a”, “b” and values are 4 and 6 accordingly.   {x: x for x in (a, b)} # --→  {4: 4, 6: 6}   Question is that I don't know how to make keys “a” and “b” instead of 4 and 6.  str(), str doesn't work. Each time x as a key gets evaluated and becames 4 or 6  Desirable output would be   {a: 4, b: 6}   Thank you!


How to not always calculate value of parameter that might not be used

I'm mostly interested in C++ answers for this but in addition C answers would be welcome too as they will probably vary. This is a simplified version of the real code to focus on my question so assume what I've written is correct :P  Imagine I have a function called process in a library. This function takes three parameters, a, b, and c Most of the time the function only needs the values of a and b to do it's job but in some circumstances requires c.  Now I want to call this from a main program. process(1, 2, very_expensive_call(55, 67, "Hello"));  Imagine that the value of c is very expensive to calculate. As it's probably not needed I don't want to calculate it unless I have to.  I don't want my main program to have to repeat the logic of knowing if c will be needed. I don't want the library to know about very_expensive_call.  So how can I organize my code to prevent the call to the expensive function while remaining both efficient and elegant?


Convert a string representation of a hex dump to a byte array using Java?

I am looking for a way to convert a long string (from a dump), that represents hex values into a byte array.  I couldn't have phrased it better than the person that posted .  But to keep it original, I'll phrase it my own way: suppose I have a string "00A0BF" that I would like interpreted as the  byte[] {0x00,0xA0,0xBf}   what should I do?  I am a Java novice and ended up using BigInteger and watching out for leading hex zeros. But I think it is ugly and I am sure I am missing something simple.


The Question is still unresolved since the duplicate answer was wrong (has a false claim as I explained in my last comment) I have seen the following question:  Why the first Linux developers chose to implement a non preemptive kernel? Hint: Linux was developed in the 90s, where personal computers mostly had only one CPU core. Which advantage non preemptive kernel provides on s single core computer and why this advantage decreases in multi core?  I am still confused why a non preemptive kernel will give any advantage, any idea or help is appreciated.


Notification saying "A new Virus is Stealing Data!" on Ubuntu 18

Recently whenever I open Firefox I get a message in notification center. It's not always the same and it keeps changing. here is an example:     It's not always this. It gives other messages too and when I click it it sends me to phishing sites. I don't know how I got it.   Could someone please help me get rid of it? I tried Clam antivirus but it found nothing.


I have a function defined as: $$S(a)=\sum_{n=1}^\infty\frac{\sin(n)}{n^a}$$ My question is for what values of $a$ is this convergent, and how can I evaulate this?  For starters, I know that $S(a)$ is definately convergent  for a $a\ge2$ since: $$\sum_{n=1}^\infty\frac{\sin(n)}{n^a}\le\sum_{n=1}^\infty\frac{1}{n^a}$$ So we can use $\zeta(a)$ as the upper limit for the series, which makes me think I can extend this convergence to $a>1$. However, I have no idea how I would evaluate this. Thanks!


Greek characters are not displayed correctly on attribute table and db manager

I have a shapefile with some churches in Greece and the characters are not displayed correctly on QGIS, although they do displayed correctly on ArcGIS. Also the other shapefiles I have with Greek characters are displayed correctly. I tried to add the shapefile multiple times on ISO-8857-9, Greek, UTF-8 and Windows-1253, but with no result. Any other way to change that?


Docker Swarm free to use? can be used in production for free?

I am a beginner so asking this silly question. Is docker swarm free to use for building cluster of docker containers? i heard it is $15/hr ? We can use swarm in production without paying anything? any limitations on it?  Also can i run specific docker containers on dedicated hosts and run some selected containers on other hosts?


How to fix 'modprobe vboxdrv' error in virtualBox?

I install virtualBox on Ubuntu 16.04, but after install and create new virtual Host shows this error:     Kernel driver not installed (rc=-1908)      The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a permission problem with /dev/vboxdrv. Please install virtualbox-dkms package and load the kernel module by executing  modprobe vboxdrv       as root. If it is available in your distribution, you should install the     DKMS package first. This package keeps track of Linux kernel changes and   recompiles the vboxdrv kernel module if necessary.  where: suplibOsInit what: 3 VERR_VM_DRIVER_NOT_INSTALLED (-1908) - The support driver is not installed. On linux, open returned ENOENT.     How to address this modprobe vboxdrv error?


Which one sounds better in formal English?

Two varieties of apple      Two varieties of apples      Two varieties of an apple   Is there any difference between these. Which one should be preferred by a native speaker?


Camera rendered view only renders a tiny square

First off, I'd like to say that my rendered view is working but when I try to view it from the camera perspective (by pressing 0) then only a small square gets rendered and the rest is still in solid view.  As you can see, it works as it should when not viewing from camera view   But when viewing from camera view, it looks like this:    As you can see, only a tiny square gets rendered and the rest is still in solid view.  I suspect that the camera setting is wrong and needs to get adjusted but I can't figure out which one it is. I tried deleting the camera and adding a new one but I still get the same problem.  I would appreciate any help.


Graph of a continuous function is closed

Let $f: \mathbb{R} \to \mathbb{R}$ be continuous. Then $G = \{ (x, f(x) ) : x \in \mathbb{R} \} $ is a closed set.  My try: Suppose $(z_n) =  (x_n, f(x_n) ) $ is sequence in $G$ with limit $(x,y)$. We must show $(x,y) \in G$. Since $x_n \to x$ and since $f$ is continuous, then we must have that $f(x_n) \to f(x) $. Since limits are unique. Then $y = f(x) $. Is this enough to conlude that $(x,y) \in G $ ? Hence showing $G$ is closed ?  thanks


Writing a program that reads in a sequence of characters until the symbol * is encountered and making use of arrays-JAVA

How can i possibly do this without knowing the size of the array beforehand? I'm totally confused. I've been trying to do this by splitting the array and what not but it's supposed to do this by using only loops. Here's different ways I've tried to do it but it doesn't stop taking user input even when it encounters a *.  1st version:  import java.util.*; public class Number11 {  public static void main(String[] args) {       String line="";     Scanner input = new Scanner(System.in);      System.out.println("You are asked to enter a character one by one and terminate the list with *");      System.out.print("Please enter a character or end it with * : ");     line = input.next();     while(!(line.equals("*")))     {         System.out.print("Please enter a character or end it with * : ");         line = input.next();         if(line.equals("*"))         {         System.exit(0);         int length = line.length();         String [] sequence = new String[length-1];         for(int i=0; i<length; i++)         {             sequence[i] = line;         }         break;         }     }   }  }   2nd:  import java.util.*; public class Number11 {  public static void main(String[] args) {      String [] character = new String[20];      Scanner input = new Scanner(System.in);      for(int i=0; i < character.length; i++)     {         System.out.print("Enter a character or press * to stop: ");         character[i] = input.next();         while(!(character[i].equals("*")))         {             System.out.print("Enter another character or press * to stop: ");             character[i] = input.next();         }      }  }  }   Your help will be much appreciated. Thanks.


What does "the repository  does not have a release file" mean?

I am trying to run sudo apt-get update, but there are errors that I don't understand:  What does this mean, and how can I resolve it? Thank you,


Is there a word for a system that requires interaction from two persons before an event happens

For example, when administering lethal injections, there are usually two buttons (each on its own harmless) that both need to be pressed by a person before it is administered.  Is there a name for such a system? I'm talking about a system that requires two people to interact to trigger the event, not a system that absolves one of them of guilt.


Let $f: G \to H$ be a homomorphism of groups. Assume that $a\in G$ and $\operatorname{ord}(a)=n$. Prove that the order of $f(a)$ is a divisor of $n$. I know that if $H$ is a subgroup of $G$, then $$|G|=|H|\cdot|\text{distinct cosets of $H$}|$$ so $|H|$ must be divisor of $|G|$, but I don't understand how to apply that logic to homomorphisms (or if that will even work). Any help is appreciated!


Which package to use for writing algorithms?

I am looking for a package that will allow me to write pseudocode  of algorithms. The pseudocode may include mathematical symbols, like \forall, \in and subscripts. But I would like also to "talk" about variables contained in the pseudocode in my text, so be able to say "In figure ... variable foobar corresponds .." and make the word foobar have the same appearance as in the pseudocode example.  I found that with the listings package I can add mathematical symbols by using: \begin{lstlisting}[mathescape]. The problem with this package is that I don't know how to make just one word have the same appearance as the words appearing inside \begin{lstlisting} ... \end{lstlisting}.  Any ideas how to do this?  Or perhaps of another package that will help solve the above mentioned problem?


How to produce an object that fills another objects?

I have a scanned object that looks like a complex bowl. I would like to make another object that fills the bowl as if it is liquid poured into the bowl. Ending up with two models that are positive and negative of each other. I hope that makes sense. I am new to this software.  Is this possible to do in Blender?


I'm not very skilled within the GIS world, however, I would like to know if it's possible to use this map:    within leaflet?  I've looked at the API for leaflet and can see that it is possible to use custom maps/tiles with the tileLayer option. However, I cannot get it to work.  Can someone point me in the right direction?


I read this in the mid-1980's and so my memory is a bit sketchy.  In the first book, there is some environmental disaster that's coming up, but the government doesn't want anyone know, so they put the scientists that are aware of the problem on a generation ship and send them to colonize a new world.  But really the government is just trying to get rid of them.  In the second book, they get to their world, but it turns out to not be that great.  Something about the atmosphere being too thick.  They decide to head out to a new planet.  In the third book, for some reason, only the kids remain on the ship and they've formed a quasi-religion based on the instruction video that was left for them.  The main antagonist was a sneaky kid that was confined to a wheelchair.  There was also an issue of the main character wanted to fix the broken things on the ship, but it was against their religion.   Any ideas?


The value of the trilogarithm at $\frac{1}{2}$

From the functional equation   $$\text{Li}_{3}(z) + \text{Li}_{3}(1-z)+ \text{Li}_{3} \Big( 1 - \frac{1}{z} \Big) = \zeta(3) + \frac{\ln^{3} (z)}{6}+ \frac{\pi^{2} \ln (z) }{6}- \frac{\ln^{2} (z) \ln(1-z)}{2}$$  one can determine the value of $\text{Li}_{3} (\frac{1}{2} )$ since   $$ \text{Li}_{3}(-1) = \sum_{n=1}^{\infty} \frac{(-1)^{n}}{n^{3}} = -\Big(1 - 2^{-2} \Big) \zeta(3) = - \frac{3}{4} \zeta(3) $$  But how does one derive that functional equation?   A similar functional equation for the dilogarithm can be derived using the integral representation $$ \text{Li}_{2}(z) = - \int_{0}^{z} \frac{\ln(1-t)}{t} \ dt $$  Is there a better way to find the value of $\text{Li}_{3} (\frac{1}{2} )$?


I know of Alexa and some people find the information useful for ranking a website... as for me, no matter how big or small my sites are, none of them are registered with stats on them, and a few clients are disappointed with me over it.   How much influence does Alexa have on website's worth? Why do people hold it's stats so highly over content of the actual site in question? Should I actually worry about Alexa Ranking?   All of the stats which I do worry about is what Google Analytics, Webmasters Tools, and Piwiki on my server tells me. Usually I can gauge how good or bad I am doing with those alone for what sections of the site is active and which is not receiving traffic for the purpose of my content.


Why didn't the Dead Men of Dunharrow continue to attack the Eye of Sauron?

After the Battle of the Pelennor Fields, Aragorn freed the Dead Men of Dunharrow. However, he could have used them in the Battle of the Black Gate too. Was the mission of the undead only to “defend”?  The army of the dead could easily have passed the Gate and drawn the attention of orcs, goblins, and trolls so that Frodo and Sam could just carry the ring without disguising themselves under restraining and exhausting armor. If they had done that, they would not have been so tired and they could have just thrown the ring down into the lava of Mount Doom. Gollum would have survived and the third giant eagle could have carried him away too.  This raises another question: Did Mithrandír bring three eagles because he was thinking that Gollum might survive? One eagle for Frodo, one for Sam, and one for old Sméagol? Or was it just for protection against Nazgûl attacks? Didn’t the Nazgûl die after Mount Doom erupted? (I know that’s a third question but at least it’s on a related topic.)     The way is shut.   It was made by those who are Dead.   And the Dead keep it.   The way is shut.


Prove that $f(x) = 0$ on the interval $[0,1]$

The function $f(x)$ is continuous on the interval $[0,1]$ and we have that   $$ \int_0^1f(x)x^ndx = 0, \quad\, n=0,1,2,\dots $$   Prove that $f(x)= 0$ on the interval $[0,1]$.   So I am thinking like this, I can expand $f(x)$ to an even function and for even $n$ I got this  $$\frac{1}{2}\int_{-1}^1f(x)x^ndx$$ and then $f(x)$ must be zero for all $x$ in this interval, is this right? What about odd $n$? Not even sure if this is the right way to attack this.  This is in my Fourier Analysis course and its in the chapter that contains orthogonal set of functions. So I need to prove this with tools within this area.


How to fix UNMOUNTABLE_BOOT_VOLUME (0x000000ED) on my Windows XP Dell laptop?

I have a Dell Latitude D410.  Running Windows XP.   I am receiving the STOP: 0x000000ED (0X899CF030,0XC0000185,0X00000000,0X00000000) blue screen.  Initially, I tried everything specified with the Microsoft KB articles. At this time, I was able to boot into the general safemode. I pulled the hard drive and was able to run chkdsk on it – it noted that it had fixed some errors, but I was still unable to boot.    I put a brand new hard drive into the laptop.  Windows XP installation worked up until the reboot, at which time the exact same error message came back up.  What I have tried (all since the new hard drive was installed):   chkdsk /R All suggested solutions in Microsoft KB articles Reseating RAM Opened laptop, reseated all connectors, looked for signs of damage (saw none) Reset BIOS options to default Ran the basic Dell diagnostics Ran MEMTEST86+ V4.10 for 15 passes (overnight).  0 Errors   I have looked at the current entry:  - I am currently in the process of downloading the Ultimate Boot CD to use as a test, but I am not holding out a lot of hope as I really doubt this brand new hard drive is bad.  Can anyone think of other areas I am missing?


Why are modulo inverses important and what do they represent exactly?

I know how to get them (extended Euclidean algorithm using the mod and the number you want the inverse of if their gcd is 1, the inverse is the number you get * the one you have in the linear combination), but I don't understand what this means.  I know inverses are important for decryption for example. I just don't quite understand how it works. And why exactly is it that you can only have an inverse when gcd(a,m)=1 ? (a being any number, m being the mod your are using)


Fighting DDoS Attack, looking for some advice

So, it appears about 2 IP addresses are overloading my HTTP server (apache) over UDP and I am unable to stop this using IP Tables. I am using CentOS 5. I managed to block some other IP addresses that were overloading TCP, but can't seem to stop the UDP.  I've narrowed down the offenders to connecting to random ports using UDP connections, but the following entry in iptables isn't working:  -A INPUT -s <offending IP> -p udp -j DROP   Can anyone offer some advice as to what I'm doing wrong?  UPDATE: I noticed that all offending incoming connections were from port 53, so did the following and it seemed to work:  -A INPUT -s <offending IP> -p udp --dport 53 -j REJECT


Therefore we don't see dark side of the moon. Is the core of the Moon closer to the Earth than the center of the moon? Or what is the reason?


What happens to the music I downloaded from Apple music if I can't make a payment?

I've downloaded lots of music from the Apple Music trial, what happens if after say 4 months I stop paying? Does all my music get deleted or do I get to keep it.


How to get an idea to use ArcGIS tools in toolbox?

I want to see the definition of any tool in ArcGIS tool box and How to enable to see the procedure to use them and option to edit the tool?


I have some Pokémon that have been in gyms for a while. I do not remember which Pokémon is in which gym. This is different from previous questions, because I know I have Pokémon in gyms. What I want to know is, how can I find out which gyms which Pokémon are in?


What sugar to use when transferring to bottle or barrel

Doing a homebrew for the first time, bought a kit to do it with; figured it be a good student method of saving money :).  Anyway, its currently in the fermenting bin, and when it comes to transferring I plan to transfer into a barrel rather than bottles.  One of the instructions is to add about 3oz of sugar per 5 gallons, but what kind of sugar would this be? Is it more brewing sugar, or can regular sugar or a different kind be used?  Thanks


Ubuntu 14.04 LTS: Shows error "System program problem detected", See details

I've attached some   and  here.      It shows the window as soon as I boot up. There also appears a (-) red minus sign which tells me that a problem occured while checking updates, and when I click "Show updates" it tells me that the Software Updater has crashed unexpectedly.  I am unable to update it (I wish to upgrade to 16.04 LTS), nor solve the problem. Any solutions?


I have a U.S. tourist visa (B1/B2), is that enough to transit via U.S. airports?

I am going to Canada, I have a valid U.S. tourist visa (B1/B2). Can I transit via a U.S. airport on the way to Canada with this visa? Logically I know I can since I am allowed to enter the U.S. but I am just making sure.


How do I get auto saves version saves / recovery to work?  Blender 2.71 just lost 15-40 minutes of work when the whole PC crashed. I have auto save set to 1-2min.   I check the 2 other versions saved and they're both from the 25th.... I was working on the file for 40min to an hour not steady today 27th I try to recover but there's no auto saves for that whole hour?  All 3 versions of the file I had (Recover auto save and blend1 blend2) were from 2 days ago not when I was working on it today.  Here's a screenshot of settings mostly default:


Posting images in chat using drag and drop

I think it will be a good idea if there is a drag and drop image posting in chat. User needs to follow many steps to upload an image using upload button.


What is the role of "*" inside of a Python3 print function?

What is the role of "*" inside of a print function in Python?  print ("Hello World!\n") print (*"Hello World!\n")   Output of the first print function is   Hello World!   Output of the second function is    H e l l o   W o r l d !    But in python 2.7 it does not work!


Here is the Issue... I have Ubuntu 12.04LTS my room mates all have windows 7 computers, I am tired of Burning CD's for them... How do I share my second HDD (Media Drive), that has all the files that always want copies of with them... In a way that they can access them from their Win7 computers?


Too large 127.0.0.1 connections with nginx - apache2

I use nginx as proxy-server apache2 and I have a problem with netstat output:  $ netstat -ntu | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n    5 109.195.36.169   6 109.195.33.205   8 194.190.59.4  14 83.246.143.75  19 109.195.33.201 725 127.0.0.1   Part of output: netstat -nt   tcp        0      0 127.0.0.1:59703         127.0.0.1:8080          TIME_WAIT tcp        0      0 127.0.0.1:11211         127.0.0.1:45684         ESTABLISHED tcp        0      0 127.0.0.1:45848         127.0.0.1:11211         ESTABLISHED tcp        1      0 127.0.0.1:8080          127.0.0.1:59867         CLOSE_WAIT   How to remove these localhost connections? Or this is normal behavior? I suspect that my site have DDOS-atack.


I have the sequence $a_n=(n^3)\big(\frac{3}{4}\big)^n$ and I need to find whether it converges or not and the limit.  I took the common ratio which is $\frac{3 (n+1)^3}{4 n^3}$ and since $\big|\frac{3}{4}\big|<1$ it converges. I don't know how to find the limit from here.


What should I do when my question is already asked and has a bad answer that is definitive, or even bounty-rewarded?

I have seen many cases where my possible question would automatically stand as a duplicate of an older one that seems to have answers, but these are bad, old, or just "no" answers providing a workaround, or trying to teach the OP about what it should be asked instead, etc.  Should I ask a new question and explain that it shouldn't be closed as duplicate although it looks like one?  Should I downvote all the answers I don't like?


If Snape knew that Pettigrew had a silver hand, why didn't Snape suggest that solution to Dumbledore's hand?

In the picture above, it shows a scene in The Half-Blood Prince where Snape tells "Wormtail" to run along before shoving Wormtail into his room with a wave of his wand.   Before Snape does, however, we are given a glimpse of Pettigrew's silver hand. If Snape knew this, why didn't he just suggest this solution to Dumbledore?  If he truly cared for Dumbledore, why didn't he just regrow the missing limb for Dumbledore instead of letting him die painfully, slowly, albeit surely?


How to open an external file from a link

Please can you tell me the command to be used for the following:  aa.pdf is an external pdf in my computer. I want then when I click on aa.pdf from the pdf generated using this latex file it should open. But it is not opening. Please suggest  \documentclass[a4paper,14pt]{memoir} \usepackage{graphicx} \usepackage{color} \usepackage{float}  \usepackage{hyperref} \usepackage{graphicx} \usepackage{subcaption} \begin{document} \pagestyle{plain}   \section{\textcolor{red}{Acknowledgement}} Practice School 1 at Guru Nanak Dev Thermal Power plant was a very interesting and innovating experience. This report is a product of valuable advice and s \newpage  \section{\textcolor{red}{Abstract}}  Thermal power plants are a  major source of generation of electricity for any developing country. Around 60\% of electricity generation in our country is met by   \newpage  \section{\textcolor{red}{GNDTP - A coal based Plant}} \section{\textcolor{red}{Introduction}}  Electricity is not just a convenience; its a necessity. It helps us live comfortably in our homes year-round, regardless of the weather. A safe, reliable and a  \section{ Report} hyperref[labelname]{aa.pdf}  \end{document}


This is a theoretical question.  So, to enable NAT on "router" machine, we enable  and all connections within "private" network are seen to external services (e.g. websites) as if that "router" initiated them.  But what about ports? Let's say I have 2 clients in private network: A and B. Imagine they both initiate connection to a service (maybe for different ones) using port 5000. How will "router" handle this? Does iptables have an internal "hashmap" or something like that which has (pseudocode):  • Proxy all requests from A:5000 via port 9000 • Proxy all requests from B:5000 via port 9001  And whenever A transfers something on port 5000, "router" forward this connection through its port 9000 and when external webserver replies, "router" receives the reply on port 9000 and forwards to A's port 5000. Same goes for B, but with port 9001 on "router".  Is it correct?  Update: I'm currently testing with WireShark and Curl. Using --local-port 5000 on both clients and connecting to the same website simultaneously with speed throttling. And Wireshark shows that both connections are using the same port. But how?


I have the card  and  in my deck, if I add the +1/+1 counter on Riddleform while it's on it's creature form from my Hadana's Climb will it stay there until the next turn that my Riddleform changes or will the +1/+1 counter disappear after then end of turn?


Can we travel in past in 4rth dimension because according to physics it is not possible to travel in past in even 4rth dimension we can only go in future.pls explain.


Let $R$ be the set of primitive $42^{\text{nd}}$ roots of unity, and let $S$ be the set of primitive $70^{\text{th}}$ roots of unity. How many elements do $R$ and $S$ have in common?  How would you work this out?  Thanks