$$\forall \ a, b \in \mathbb{R}, prove \hspace{5mm}\frac{|a+b|}{1 + |a+b|} \leqslant \frac{|a|}{1+|a|} + \frac{|b|}{1+|b|}$$  I decided to take different cases to solve this problem.  For $a, b \geqslant 0$ and for $a, b < 0$, the inequality is obvious as $$\frac{|a+b|}{1 + |a+b|} = \frac{a}{1+|a+b|} + \frac{b}{1+|a+b|}$$ when $a, b \geqslant 0$ and $$\frac{|a+b|}{1 + |a+b|} = \frac{-a}{1+|a+b|} + \frac{-b}{1+|a+b|}$$ when $a, b < 0$  For $a \geqslant 0, b < 0$ and $|a| > |b|$, I was able to prove the inequality. However, I'm unable to prove in the case where $a \geqslant 0, b < 0$ and $|a| < |b|$.


The range of function $f(x,y)=\frac{x+y}{1+x^2+y^2}$

Given that  $E=\{(x,y) \in \mathbb{R^2}:|x| \leq1,|y|\leq1\}.$ function $f(x,y)=\displaystyle \frac{x+y}{1+x^2+y^2}$  where $f:E\to \mathbb{R}$ Then the range of $f$ is  $1)$ connected open set $2)$ connected closed set $3)$bounded and open set $4)$closed and unbounded set  Solution i tried- The given function is continous ,so a continous function maps a connected set to connected set and also $E$ is a compact set so its image under the continous function will be compact ,from all this option $2$ will be true ,but my answer is wrong , Please help


4K monitor not showing in 4K on my Macbook Pro (late 2011)

I just bought a new monitor (the LG 27UL500) which should support 4K to connect with my Macbook Pro. I've connected my Macbook Pro with an Mini DisplayPort to HDMI connector (which should support 4K) to my monitor.   But now my Macbook only gives me the option to set it to 1080p. I've tried to 'hack' my monitor with SwitchResX to 2560x1600 but the quality seems to stay the same.   Is it my Macbook Pro video card that can't handle the 4K? Because on  it says that my Macbook should be able to handle a second screen of 2560x1600. It’s not 4K but still better then the 1080p I have right now.  Having a 4K monitor which only displays 1080p is kinda useless. Can someone help me get this monitor to display the max possible resolution?  Specs of my Macbook Pro: MacBook Pro (13-inch, Late 2011) Processor: 2,8 GHz Intel Core i7 Memory: 16 GB 1333 MHz DDR3 (was originally only 4GB) Videocard: Intel HD-video 3000 512 MB


I have deployed SSL certificates on various websites however this wildcard SSL certificate is totally new to me. I have question that If I am buying a SSL certificate *.example-private.com, Will it work for *.staging.example-private.com Or Do I have to buy a different wild card SSL for staging site. I am going to implement this on new sites.


Is it possible to send a Unicode string to the currently focused window as a series of key presses?

I have a program that converts user input to a Unicode string (for example, テスト), and I want to "send" that string to the currently focused window by simulating keyboard presses, as if the user typed that string directly. Currently the best I can do is to copy the string to the system clipboard and programmatically press the Ctrl+V keys, but that seems like a workaround. Toolkit.getDefaultToolkit().getSystemClipboard().setContents(new StringSelection("テスト"), null); Robot robot = new java.awt.Robot(); robot.setAutoDelay(100); // otherwise the keys are pressed and released too quickly robot.keyPress(KeyEvent.VK_CONTROL); robot.keyPress(KeyEvent.VK_V); robot.keyRelease(KeyEvent.VK_V); robot.keyRelease(KeyEvent.VK_CONTROL);  Is there a way to programmatically type Unicode characters, akin to robot.keyPress(KeyEvent.VK_KATAKANA_TE), or even robot.keyPress('テ')?


couldn't write to /etc/fstab with "sudo cat mytext >> /etc/fstab"

I usually use Debian, and use root commands after su. I am new to Ubuntu, not familiar with sudo syntax.  sudo cat fstab_new_text >> /etc/fstab   This results in   bash /etc/fstab: permission denied   I can edit the file in a terminal with vi  sudo vi /etc/fstab   The man pages did not help me.  Thanks in advance for any clue.


Can I apply for a transit visa if I stay two days in Dubai before going to a third country?

Actually there are two questions. I'm nicaraguan but live in Japan. I will go to Zambia, with a transit via Dubai. I will stay two days in Dubai before continuing my trip to Zambia.  What kind of visa do I need? Can I apply for the 96-hour transit visa? Or a single-entry tourist visa?  When I return to Japan, I will transit in Dubai, but just stay in the airport. Do I need a transit visa?


Intersection of finite Galois extensions is Galois

If K and L are finite Galois extensions of F, then show that the intersection of K and L is Galois over F.  I was trying to use Galois group of the intersection and show that if the fixed field is NOT F then we can extend an automorphism to K and get some contradiction.  Any help?


Show that $t^n-1 \mid t^m-1 \Leftrightarrow n\mid m$

I want to prove the following lemma:   $t^n-1$ divides $t^m-1$ in $F[t, t^{-1}]$ if and only if $n$ divides $m$ in $\mathbb{Z}$.   I have done the following:   $\Leftarrow $ :   $n\mid m \Rightarrow m=kn, k \in \mathbb{Z}$  $t^m-1=t^{kn}-1=(t^n)^k-1=(t^n-1)(t^{n(k-1)}+\dots +1)$   So, $t^n-1\mid t^m-1$.   Is this correct?   How could we show the other direction?


Negative Gravity Fields and Time Dilation

Question: Some physicists believe that it is possible to have . My questions is would this negative mass create a negative gravity field, exerting a negative force on positive masses? And if so, would the negative gravity field cause an opposite effect on time, possibly slowing it down?  My attempt: I feel like it would exert a negative force because of the Universal Law of Gravitation. So we have a negative force exerted from a negative mass ($m_1$) on a positive mass ($m_2$):  $$ F_{+mass} = G \frac{(-m_1) m_2}{r^2} \vec{r} $$  This would mean that the gravity vector field is now pointed away (I think) from the center of gravity rather than towards it, aka negative gravity.  Now I am not familiar enough with the time dilation equations to take a shot at that but any search I have done comes up empty on that matter. But intuitively, it seems to me that time dilation would also work backwards.


Is there a tool for generating journal names' abbreviations

Having a BibTeT file with full journal titles in it, I'm looking for a tool to construct a list of abbreviations following  (it specifies how to abbreviate individual words, which should make it straightforward to generate abbreviations for any title).  I'm ware of JabRef, but it requires a list of title-abbreviation pairs and I don't want to do one by hand if I don't have to.  (I should add that the lists available from JabRef website do not cover the titles I have).


Please tell me what are Graham Cracker Sheets? I live in Australia and have not heard of them but I'm sure we have an equivalent, any advice appreciated.


Is it possible for average students to get admitted in good colleges for MS?

So, if I get a 320 plus GRE score and have a CGPA of 7.0 with no research paper but a lot of social and extracurricular activities, is it possible for me to get admitted to a good college in USA? I have studied computer science and I am interested in getting a MSc degree in Artificial intelligence or Data Science. If yes, how much exceptional my SoP and LoRs should be, since I am an average student and I don’t think I would be getting exceptional LoRs. More importantly, is it possible for me to get admitted in top colleges like Georgia tech (not CMU or UCLA since they are too top notch and I don’t think they would accept me)?


Long sites break the layout on the front page

The long name pushes the stats to a weird place. And what's with the "Stack Exchange" at the end anyway?


Get-PnPListItem Not returning all the Fields

I am new to using PowerShell with regards to pulling data from SharePoint using PnPListItem.  I have my code below:  Write-Host "Please enter URL of the SharePoint site:" $url = Read-Host   Write-Host "Please enter List Name of the SharePoint site:" $ListName = Read-Host   Connect-PnPOnline -Url $url -UseWebLogin Get-PnPListItem -List $ListName   It is getting all the row that I need, the problem is that it returns only the ID, Title, and GUID columns.  I need all the columns in my value display. Any advise?


I am having difficulty uploading a document to arXiv because of compiling errors. I am using biblatex 3.5 with biber 2.6. It compiles fine on my computer. Here is a MWE which fails on arXiv. I compile with PDFLatex, biber, PDFLatex, etc. I then upload the .bbl file:  \documentclass{article}  \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc}  \usepackage[backend=biber,url=false]{biblatex} \bibliography{MyLibrary3}  \begin{document}  Words \cite{BoydParikhChuPeleatoEckstein2011_distributed}  \printbibliography  \end{document}   This has .bib file:  @article{BoydParikhChuPeleatoEckstein2011_distributed,   title = {Distributed Optimization and Statistical Learning via the Alternating Direction Method of Multipliers},   volume = {3},   url = {http://dl.acm.org/citation.cfm?id=2185816},   number = {1},   journaltitle = {Foundations and Trends\textregistered in Machine Learning},   author = {Boyd, Stephen and Parikh, Neal and Chu, Eric and Peleato, Borja and Eckstein, Jonathan},   date = {2011},   pages = {1--122} }   I get the following error when I try to upload to arXiv.   Package biblatex Warning: File 'arXivSubmission.bbl' created by wrong version.  (./arXivSubmission.bbl ! Undefined control sequence. l.21 \sortlist [entry]{nty/global/} ?  ! Emergency stop. l.21 \sortlist [entry]{nty/global/} ! ==> Fatal error occurred, no output PDF file produced! Transcript written on arXivSubmission.log.   I'm using the latest version of biblatex and biber, and it's not clear what version arXiv uses. To get around this error. I tried to upload my version of biblatex.sty. Doing this gives me the following error:  ! Missing \endcsname inserted. <to be read again>  \blx@datamodel@constant@optiondatatypes  l.5584 ...odel@constant@optiondatatypes\endcsname}  ?  ! Emergency stop. <to be read again>  \blx@datamodel@constant@optiondatatypes  l.5584 ...odel@constant@optiondatatypes\endcsname}  ! ==> Fatal error occurred, no output PDF file produced! Transcript written on arXivSubmission.log.   In the biblatex.sty file that I uploaded, here is the line that seems to be causing errors (5584):  \expandafter\expandafter\expandafter\docsvlist\expandafter\expandafter\expandafter{\csname blx@datamodel@constant@optiondatatypes\endcsname}   Doing this with bibtex instead of biber results in the exact same errors. Any help or general advice on uploading to arXiv would be greatly appreciated!


"Very not fair" vs "not very fair" which is correct

I was in a situation where I wanted to let the other person know that whatever they said was not fair to me or to the point we were discussing so I used "This is not very fair" and then realised may be I was wrong in terms of sentence usage. Please suggest which one should be used.


Prove that for every set $A$, there exists and ordinal $\alpha$ which does not have surjective function from $A$ over $\alpha$: $$(\forall A)(\exists \alpha)[\lnot(\vert\alpha\vert\leq^*\vert A\vert)]$$ We say that  $\vert A\vert\leq^*\vert B\vert$ if there is surjection from $f:B\to A$. I am trying to solve this problem but I get completely lost in what I have to do. Set theory is a new thing for me and it is really hard how to begin. I would be very thankful is someone gives me a direction from where to start or any ideas on how to solve this problem. Thank you in advance!


Essentially, I wonder that if X is a plural noun, should we use a plural or singular verb in a sentence such as "X are a subject that [verb] ..."? I believe that we should always use the singular verb form there (for example, "Eatable flowers are a subject that comes up ..."). However, I was surprised to find this sentence on the  page:     Eatable flowers are a subject that come up in almost all cooking classes eventually and I am a big fan of them.   as well as this on Google Books:     Tools are a subject that come up at our house from time to time.   I think they are typos, but I would like a double check to be sure.


How can I get the size of an Amazon S3 bucket?

I'd like to graph the size (in bytes, and # of items) of an Amazon S3 bucket and am looking for an efficient way to get the data.  The  tools provide a way to get the total file size using s3cmd du s3://bucket_name, but I'm worried about its ability to scale since it looks like it fetches data about every file and calculates its own sum. Since Amazon charges users in GB-Months it seems odd that they don't expose this value directly.  Although  returns the number of items in a bucket,  doesn't seem to expose it. I could do s3cmd ls -r s3://bucket_name | wc -l but that seems like a hack.  The Ruby  library looked promising, but only provides the # of bucket items, not the total bucket size.  Is anyone aware of any other command line tools or libraries (prefer Perl, PHP, Python, or Ruby) which provide ways of getting this data?


Can I create a self-answered question and add my website as a reference?

I've some interesting Q&A posts about programming in my personal blog and I would like to post these questions (and the respective answers) on Stack Overflow, because a lot of people can be helped (for real, you can't find the answers easily on the web).  I know that users are encouraged to create self-answered questions, but can I create a self-answered question that is already available at my website? And my main question: can I link my blog as a reference for the answer of the question?   Hope that I've made the question clear, but ask me if you don't get something.


Is there a more efficient way to write a series of equations?  \begin{equation*}     B'(x)=0 \end{equation*} \begin{equation*}     -\frac{1}{x^2} + \frac{1}{(1-x)^2}=0 \end{equation*} \begin{equation*}     \frac{-(1-x)^2 +x^2}{x^2(1-x)^2}=0 \end{equation*} \begin{equation*}     -x^2+2x-1+x^2=0 \qquad \text{Con $x\neq 0 \wedge x\neq 1$} \end{equation*} \begin{equation*}     2x-1=0 \end{equation*} \begin{equation*}     x=\frac{1}{2} \end{equation*}


Can we use NPM modules or libraries from CDN in LWC custom component

How can we use npm modules in LWC? I'm trying to use  library in my LWC component. This library is also available in CDN, can we use it in a static resource?


Nullpointerexception when I perform depth first search

Suppose area1 has three contents 2,3,4, area2 has three contents 1,2,3 and area3 has two contents 1,2. m is the map that keys are locationid and values are list of contentid. For example, area1 has the map (1,{2,3,4}). Each area choose 1 content and find all the combination. I use dfs (recursion) to solve this problem but there is a nullpointerexception in line1. The intermediate is a list of string and i iterate through the list and their types are both string, why there is a null pointer exception? This is a specific condition in nullpointerexception and it is not duplicate.  public static List<String> dfs(String digits,Map<String, List<String>> m) {         List<String> result = new ArrayList<String>();         if(digits.length() == 0){             return result;         }         if(digits.length() == 1){             return m.get(digits.charAt(0));         }         List<String> intermediate = dfs(digits.substring(1, digits.length()),m);         for(String first : m.get(Character.toString(digits.charAt(0)))){             for(String rest : intermediate){           // line1                 result.add(first + rest);                 }             }         return result;     }  public static void main(String[] args) {     // TODO Auto-generated method stub     String digits="123";     Map<String,List<String>> selected=new HashMap<>();     selected.put("1", new ArrayList<>(Arrays.asList("4","2","3")));     selected.put("2", new ArrayList<>(Arrays.asList("1","2","3")));     selected.put("3", new ArrayList<>(Arrays.asList("1","2")));     dfs(digits,selected); }


I have sample CSV data file with 1M records with 1 date (14/03/2017 00:11:17) only. I need to generate 6 month data from this sample CSV file. Bash script taking 20 Minutes to generate 1 day data. DATA SAMPLE  '12/01/2017 03:22:17,sampledata,1234,sample,123455,67546464'  EXPECTED RESULT  '01/01/2017 03:22:17,sampledata,1234,sample,123455,67546464'  '02/01/2017 03:22:17,sampledata,1234,sample,123455,67546464' to  '30/01/2017 03:22:17,sampledata,1234,sample,123455,67546464'


how to derive schrodinger equation from heisenberg equation?

canonical commutator relation(CCR) can be derived by switching classical poisson bracket to quantum commutator and this process is called as canonical quantization.  $[x_i,p_j]_{PB}=\delta_{ij} →\frac{1}{ih}[x_i,p_j]=\delta_{ij}$  and also, the classical hamilton's equation of motion can be written by this quantum meachanical language,  $ \frac{dp}{dt}=[p,H]_{PB},\frac{dq}{dt}=[q,H]_{PB} →i\hbar\frac{dp}{dt}=[p,H],i\hbar\frac{dq}{dt}=[q,H]$  This is the heisenberg equation of motion as far as I know.  I want to know, how to derive schrodinger equation from this heisenberg equation of motion.  Maybe it looks like a stupid question. But please help me.


minimum possible absolute temperature in the universe?

Sorry guys i went wrong in my previous question , actually my question is what is the minimum possible absolute temperature in the universe of what ever substance...?


Term for using "thingy-esque" phrases rather than a common word

{This question came to mind because of the recent question ..  }  In my opinion, in English, it's reasonably common that—strangely enough—there is no word for a certain reasonably common thing. And indeed, speakers prefer to use an ad-hoc description for the thing in question on an ongoing basis, rather than, as you'd probably expect, a specific or technical word falling into general use and coming to be "the word" for the thing. {Contrast milieu such as say Germany or Japan, where the culture, within 12 seconds, codifies exact, specific, universally-accepted terms for anything that comes along, whether a cultural phenomenon, technical object, or the like.}  I think of this as "the Thingy substitution", or the things in question as 'thingy things' because, well, they are usually referred to as     the thingy that...   The perfect example is      the thingies on jigsaw puzzle pieces.   (Note that, 100% of English-native speakers will understand exactly what I am referring to.)  To repeat, native English speakers—in my opinion—prefer to stick (even over decades) with ad-hoc thingy-esque multi-word descriptions rather than adopting a new word generally accepted.  {On the other hand, of course, the etats-unis in particular is notorious for generating zillions of acronyms and other coinages—however, I don't think the two concepts are at odds, both are true.}  Now there's possibly a term for this phenomenon among linguists e.g., "grasp words", "thingy words" or "ad-hoc non-naming conventions" etc.   (a) Does anyone know such a term? (b) Indeed, does anyone agree that this is a phenomenon amongst particularly English speakers? (c) Indeed, is this all well-known and explored by academic linguists/etc and I'm just behind the times?


In order to get Harry out of the Dursleys' house, the aurors decided to come up with a plan to use polyjuice potion to create seven Harry Potters, providing confusion over who the Death Eaters should go after. This was to avoid the problem of apparating out of the house, since Harry still had the Trace and the Ministry would know where he went. (Floo powder and portkeys also had some Ministry oversight, so were off the table).  Why didn't Harry just leave while wearing the Invisibility Cloak, perhaps going out at the same time that the Dursleys were moving out? That doesn't involve casting any spells and nobody can see Harry. So long as he's smart enough to get out without having any strangely opening doors, I think he'd be safe. Heck, since the Cloak is large enough to cover three children, perhaps he could even ride his broomstick while wearing it. Sure, there's the homenum revelio spell, but I can't imagine the Death Eaters casting it continuously for days on end.  Why didn't Harry leave the Dursleys' house under the Invisibility Cloak instead of having the Seven Potters plan?


Why does chat profile reputation seem inconsistent?

The reputation on  is supposed to be . Now why is it that 's  does not include his MSO reputation, but otherwise includes all 200+ rep accounts' reputation (including SO, of course)?  does include all my 200+ rep accounts including MSO.


Does Phantasmal Force Have a Range Limit After Casting?

Phantasmal Force      2nd-level Illusion      Casting Time: 1 action      Range: 60 feet   If I were to cast this spell, and either I or the target otherwise become greater than 60 feet away from each other during the duration, would the spell fail/end?  There is precedent in other spells like Witch Bolt which specifically says the spell ends if the target is outside the spell's range, but Phantasmal Force never specifies such a condition.


Consider the following command:  echo ’.dump’ | sqlite bacula.db > bacula.sq   What is it doing and what does | do?  Maybe someone could point me to a manual about piping, or explain what is going on. Thanks.


Find $a_1/a_2$ in the Laurent series expansion of $\frac{1}{2z^2-13z+15}$

Let $\sum a_n z^n $ be the laurent series expansion of $f(z)=\frac{1}{2z^2-13z+15}$ in the annulus $3/2 <|z|<5$.   I am interested in finding $a_1/a_2$.  Efforts:  $f(z)=1/(2z-3)(z-10)$  So using partial fraction decomposition $$f(z)=\frac{1}{7} (\frac{1}{z-10}-\frac{1}{2z-3})$$  How should I proceed from here? Thanks in advance.


How to avoid exceeding normal page limits after revision?

I wrote a manuscript that was the maximum length (without any page charges) and sent it to the IEEE Journal of Biomedical and Health Informatics. Now the revisions have come. I am in the process of revising it, but I see that after revision there may be an addition of 1 or 2 pages more. Now for these 1 or pages I have to pay approximately $250 which I don't have. How do I avoid this over-length after incorporating all the revisions?


Are Pyrex casserole dishes safe for use on electric stovetops?

Would it be okay if a Pyrex baking dish is used on an electric stove top to reheat food?


Could the universe's antimatter be hiding in black holes?

As far as we know almost all the mass in the universe is matter, not antimatter. There are three scenarios:   The universe started off with more matter than antimatter and the small amount of antimatter has mostly been converted to energy via collisions with matter The universe started off with equal amounts of matter and antimatter and some unknown process caused the situation we see today The universe started off with less matter than antimatter and somehow the ratio reversed (I've never heard this discussed as it seems so unlikely)   We reason that mass is matter because if there were large amounts of antimatter they should produce antimatter galaxies, which would give off huge amounts of energy when they interact with matter galaxies. This has never been observed so we conclude that all galaxies, therefore all mass in the universe is matter.  As I understand it there are two main types of black holes, stellar remnants (the collapsed remnants of dead stars with more than two solar masses) and super-massive black holes at the centre of many galaxies, including one thought to be at the centre of our own galaxy.  Stellar black holes are obviously originally composed of matter, for the same reason that all galaxies are composed of matter.  We don't know how super-massive black holes formed. Is there enough mass in them to contain all the antimatter in the universe if matter and antimatter were originally created in equal quantities? I realise this shifts the unknown mechanism from "why was more matter created than antimatter" to "why is antimatter more likely to form super-massive black holes" but is this hypothetical scenario possible?


I have checked many dictionaries but there is no one opposite of 'sin'.


Could you generate a lot of electricity in space?

I was just thinking about the fact that if you threw a ball or any object out into space where there is no other forces or gasses it would continue on forever, so say you had a turbine and you spun it and that would keep going for a very long time, couldn’t you basically generate infinite electricity?  I have no idea if this question is dumb as I’m only in year 9 and not done a lot on physics in that much depth...


LM1084, should I leave the copper area connected to the TAB floating?

I am using the  in a DDPAK package as a 5V USB voltage regulator on 4-layer board.  The TAB of the package is internaly connected to pin 2 (OUTPUT).    I am not sure what to do with the copper area connected to the TAB. Which of the following options should I choose:   leave the copper area connected to the TAB floating connect the copper area connected to the TAB to pin 2 (OUTPUT) use the copper area connected to the TAB as a the primary OUTPUT connection, leave pin 2 floating


I have lost both gmail id and password, how can I recover it

I have forgotten both my email id and password, only the mobile number is with me. Please help me to find out it.


How should I use came and just now together to say: I have already come but only a few minutes back?   I came just now.   or   I just now came.


Notifications not working in Android app

I'm not entirely sure this is the right place, but here goes.  On an Android One device (Xiaomi Mi A1) with Android 8.1 I do not receive notifications. They are enabled in app settings, in system as well. When I log in there are new in-SE notifications in the form of a red number in upper right hand corner.  My best guess is that this is connected to more aggressive background optimizations in newer Android versions. For reference I receive Facebook Messenger messages properly and sleep tracking in Sleep as Android works as well.


Confused about the possibility of different differentiable structures.

In Loring Tu's "An Introduction to Manifolds" an atlas on a manifold is a collection of coordinate charts that are pairwise compatible and cover the manifold. A smooth manifold is defined to be a topological manifold together with a maximal atlas or differentiable structure. The maximal atlas is constructed by taking an atlas and appending all coordinate charts that are compatible with the atlas and using this he shows that any atlas on a locally Euclidean space is contained in a unique maximal atlas.  He also later shows that for any chart on a manifold, the coordinate map is a diffeomorphism onto it's image.   My question arises when Tu mentions in an aside that every compact topological manifold in dimension four or higher has a finite number of differentiable structures. What I don't understand is how it is possible for a smooth manifold to have more than one differentiable structure. Doesn't the fact that for any chart the coordinate map being a diffeomorphism coupled with the fact that composition of smooth functions is smooth mean that any two coordinate charts on a manifold are compatible and thus they must all belong to one maximal atlas? How is it possible to have another? Am I not understanding the word "maximal" or atlas or some other concept?


Show that,   $$2\arctan\left(\frac{1}{3}\right)+2\arcsin\left(\frac{1}{5\sqrt2}\right)-\arctan\left(\frac{1}{7}\right)=\frac{\pi}{4}$$  There is a mixed of sin and tan, how  can I simplify this to $\frac{\pi}{4}$  We know the identity of $\arctan\left(\frac{1}{a}\right)+\arctan\left(\frac{1}{b}\right)=\arctan\left(\frac{a+b}{ab-1}\right)$


I started studying flip-flops recently and I am stuck at this point: At some video tutorials, people explain the SR flip-flop like this:  So they use NAND gates, producing a transition table like this: |     t     | t+1 |  S  |  R  |  Q |  0  |  0  |  INVALID |  0  |  1  |  1 |  1  |  0  |  0 |  1  |  1  |  ?  However, some other people explain the SR flip-flop using NOR gates:  (source: ) which has a different transition table. Are both correct? Why do both exist?


Let $N$, $K$ be sub-modules of $M$ with $I=\mathrm{Ann}(N)$, $J=\mathrm{Ann}(K)$. Show $I+J$ is a proper subset of $\mathrm{Ann}(N \cap K)$.

Let $N$ and $K$ be sub-modules of $M$ with $I=\operatorname{Ann}(N)$ and $J=\operatorname{Ann}(K)$. Show that $I+J$ is a proper subset of $\operatorname{Ann}(N \cap K)$.


What is the best approach to write a literature review paper?

I'm completely new to writing a review paper, so how would I best write it? Do I need to read every single paper? Or just a few sections like the introduction and results and get the info from them? How would you approach this?


Depletion-mode P-channel MOSFET availability?

I need a P-channel depletion-mode MOSFET for a circuit I'm building. However, there is no model available in  that I have found, nor is there any available that I have found to buy online.   How can I simulate this kind of MOSFET in LTspice, and where can I get one?


Which command should I use for displayed equations?

A number of related questions have already been asked about this issue:       and even    But I'm still confused by the conflicting suggestions that have been given so far. So I'm trying again.  Which should be the preferred command to produce a displayed equation in my LaTeX documents?  So far the suggestions indicate that one should use \[ ... \], maybe \begin{equation*} ... \end{equation*}, or maybe even the gather* or align* environments from amsmath.  And one should definitely avoid using either $$...$$ or the eqnarray environment.  Now I have to say that, from a language perspective, I have a strong preference for the equation* environment because it is less cryptic than the \[ ... \] notation and it is  the most accurate.  So, is it fine to use equation*? Maybe only after loading amsmath? Or should the equation/equation* environment be redefined to something else so that spacing, package support, or whatever is improved?


Prove that $\lim_{x \to 0} \frac{x - \sin x}{x^3} = \frac16$ using notable limits

Can we prove that $\lim_{x \to 0} \frac{x - \sin x}{x^3} = \frac 16$ using just algebra, trigonometric theorems and notable limits $\left( \mathrm{i.e. }\quad \frac{\sin x}{x} \to 1 \quad \mathrm{and} \quad \frac{1 - \cos x}{x^2} \to \frac 12 \right) $ and no l'Hospital rule, no series expansion, no Taylor series?


There's no option to disable Bluetooth permanently but under energy settings you can select to disable both Bluetooth and wifi when not in use. Does this mean that Bluetooth gets disabled automatically? I never use it and want to save power.


Why we define the completeness of a space by the converge of a Cauchy sequence rather than a normal sequence?

The intuition of the completeness to me is that the limit of any sequence converges to the point inside the set itself. But why we define a set to be complete as any Cauchy sequence converge into the set itself? It seems a more complex definition than a simple convergent sequence. Why we use Cauchy sequence rather than a simple sequence?  For the simple sequence, can we use $\lim_{n\rightarrow \infty }x_n=x$?


I can not identify my bike and these serial numbers can you help.?

I can not identify my bike and these serial numbers are not pulling up anything SNACY 12H11569 can anyone help me find the name of this bike frame ?


This is the achievements drop-down on Ask Ubuntu:    It doesn't look very good. The same happens on Meta SE - so it's a new and old top-bar issue.    Mac OS 10.12.6, Chrome 60.0.3112.113. Also happens in Safari 11.0 and Chrome incognito mode with no extensions, so is not a user-script issue. Zoom at 100%.  Does not happen with Chrome on Windows 10.


Did Darth Sidious cause Anakin's virgin birth?

that Anakin was conceived by midi-chlorians after Shmi told him there was no father.  Senator Palpatine tells Anakin that his former master, Darth Plagueis, learned how to influence midi-chlorians to create life.  The thought just occurred to me: did Palpatine learn this skill from his master, and create Anakin himself by manipulating the midi-chlorians? He was always very interested in Anakin, and seemed to set up his plans very far in advance. So it makes sense if those assumptions are true.  After I realized this might be a possibility, in my research I found this small  discussing a very similar thing. It goes into further suppositions about this theory, but doesn't definitively answer the question.  Is this theory ever confirmed or denied in any expanded universe canon?


I'd like to try PHP7.0 on Debian Jessie and am trying to install it from sid. However,  depends on  which depends on php-common > 18 while  in sid is at 17. Does this mean it's simply impossible to install php7.0 from this distribution at the moment? Why is that?  I know that it is possible to install from source as explained e.g. , I'm just asking about the official packages.    Note: the packages in sid have been fixed and it is now (Jan 6, 2016) possible to install from there.


How to refer variable defined in sub shell in parent shell. command grouping is difficult in my case. What would be the alternative.


ArrayList returning NullPointer Exception || Java || OOP

Hey can someone please help me understand why I keep getting a null pointer exception while trying to run this? I was just trying to learn arraylist for a course I am taking.  ////////////////////////////////////////////  public class Address {     int houseNumber;     String roadNumber;     String areaName;     String cityName;   public Address(int hn, String rn, String an, String cn){     this.houseNumber = hn;     this.roadNumber = rn;     this.areaName = an;     this.cityName = cn; }   public String toString() {     return "House # " +  this.houseNumber + "\nRoad # " + this.roadNumber + "\n" + this.areaName + "\n" + this.cityName;  }    }   /////////////////////////////////////////////////  import java.util.ArrayList;  public class AddressReferences {  ArrayList<Address> myCollection = new ArrayList<Address>();   public void addAddress (int hn, String rn, String an, String cn) {     myCollection.add(new Address(hn,rn,an,cn)); }  public void printAddress () {     for ( Address i : myCollection){         System.out.println (i);       } } }   //////////////////////////////////////  public class Test {  static AddressReferences ar;   public static void main(String[] args){      ar.addAddress(46, "9/a", "Kotol", "Dhaka");     ar.addAddress(44, "9/a", "Kotol", "Dhaka");     ar.addAddress(28, "9/a", "Kotol", "Dhaka");     ar.addAddress(89, "12/a", "Kotol", "Dhaka");     ar.addAddress(60, "7/a", "Kotol", "Dhaka");       ar.printAddress();      } }


Is the sentence "I didn't marry you because you were rich." same as " I married you not because you were rich but for another reason."


I am very uncertain about when to use "most of whom," "most of who," or "most of which."  Please give concrete examples instead of only rules like, "this is the subject, so you should..."


Does personified Death really exist in Harry Potter?

I went through the last book, Harry Potter and the Deathly Hallows, yesterday and a question popped in my mind: Does Death, the supposed creator of the Deathly Hallows, really exist in the Harry Potter universe? Dumbledore thought otherwise and I am with the same school of thought.  By the way who created the deathly Hallows actually?  Update:  1) Why were the brothers so sure that the hooded figure was death(couldn't it be a more powerful wizard playing with them)  2) Couldn't, Beedle and the brothers create this story?


I'm playing on a Survival world with cheats on, "easy" difficulty, and at night in-game. I didn't have a sword or anything to make a sword with, and I was starving, so I switched to Creative to give myself a stack of food and a bed to set my spawn point. When I switched back to Survival, I couldn't destroy or place blocks. I'm on single player, and my Internet is fine, and I can destroy blocks still if I switch to creative. I've tried resetting the button one, and reloading the map, and it still doesn't work. I've even tried deleting everything I gave myself in Creative. This happened before on a different world and I ended up deleting it.  This only happens on this world. How do I fix it?  If I know I'm in the correct game mode, what else can cause this?  Are there different causes in multiplayer?


How to multiply lists and set a single variable?

I'm trying to create a long list, without having to manually type it out every time. I'm using this currently (replaced longer number with 0 for simplicity):  mylist = [[0]*5]*5   Which is:  [[0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0], [0, 0, 0, 0, 0]]   Printing each row, this list looks as follows:  00000 00000 00000 00000 00000   When I try to change one of the numbers (let's say first row and first item), it sets all of the rows' first item.  mylist[0][0] = 1   Printing each row:  10000 10000 10000 10000 10000   How do I set only the item I want?


Remap a key combination to another combination, e. g. Super+Ctrl+Shift+J -> Ctrl+Shift+Left

I want to implement an addition key layer, so that I can access non-alphanumeric keys without having to move my wrists.  I've been using Autokey for this purpose, but the experience was unsatisfactory: it had occasional lags and let original keystrokes slip into certain apps.  So I need a low-level solution.


when i enter the password "ahmad" the code doesn't execute as it true, i don't know what is the problem   but if i define variable pass = "ahmad" it is working very well  but i want to make the user enter the password by himself   public class main {  static Scanner uinput= new Scanner(System.in);  public static void main(String[] args) {       String pass;      while(true){      System.out.print("Enter the password: ");     pass= uinput.nextLine();      if(pass== "ahmad"){         System.out.println("It is working");     }      else System.out.println("failed");      }  }   here is the console result:  Enter the password: ahmad failed Enter the password:


How to draw a tikz diagram with a rectangular u-shaped edge connecting two blocks?

I am trying to draw the red arrow between the two blocks     However, I have no idea how to do it. Could please someone draw it and show me code?


Is it possible to upgrade the AMD E-300 APU on a laptop?

I read that this processor is BGA. That would mean that it is soldered to the motherboard? Can an average laptop technician replace it?  This processor is very slow, it scores only 600 on the Passmark CPU Benchmark.


Adobe Photoshop: Creating a matrix grid / collage of images

Is there a convenient way of creating a grid, or a collage of images, without having to do it manually?  Ideally I want a 64x64 square grid of images that are each 100px * 100px. I've seen them done a few times, I think Groupon used to have one.   Are there any plugins that exist for this or any way of doing it without having to resize each image manually?


Because my laptop fan was spinning up for no reason, I had a look at the CPU usage and I see  svchost with 12.5% CPU, which is basically a full core.  Now, I'm aware that  svchost runs services and I know how to display the services it runs in Task Manager or Process Explorer ().  Now I know which services are run, but I don't know which service eats the CPU time. I could disable one service after another, but I don't really like doing this (it could break things that are currently in use and I could forget turning the service back on later).  Therefore I'd like to know whether it's possible to instruct Windows to run only one service per svchost the next time I boot my PC. While I might have the slight disadvantage of several processes, I could immediately find out which one it is and it would be a much easier decision of whether or not to stop or restart the service.


Find $f(x)$ such that $f(x)+f\left(\frac{1}{x}\right)=f(x)\cdot f\left(\frac{1}{x}\right)$

Given a polynomial $f(x)$ of n degree such that $$f(x)+f\left(\frac{1}{x}\right)=f(x)\cdot f\left(\frac{1}{x}\right)$$ Find the polynomial  I've tried considering $f(x)=\sum \limits_{i=1}^{n} a_{i}x^{i}$ and after a number of steps I finally arrived at the answer.However I am not convinced.Is there a better way to solve this functional equation. Thanks in advanced!


Do there exist an infinite number of 'rational' points in the equilateral triangle $ABC$?

Let's call a point $P$ which satisfies the following condition 'a rational point'.  Condition: Each distance $PA, PB, PC$ from a point $P$ to three vertices $A, B, C$ of an equilateral triangle $ABC$ which has edge-length $1$ is rational number.  I'm interested in this point because I found the following three:  1. There exist an infinite number of rational points on an edge of the equilateral triangle $ABC$.  2. There exist an infinite number of rational points on the circumference of the circumscribed circle of the equilateral triangle $ABC$.  3. There exists a rational point in the equilateral triangle $ABC$.  Supposing that $A(0,\frac{\sqrt3}{2}), B(-\frac12,0), C(\frac12,0)$, one example for the above 3 is the following: $$P\left(\frac{61}{2058},\frac{220}{1029}\sqrt3\right), \left(PA, PB, PC\right)=\left(\frac{73}{147}, \frac{95}{147}, \frac{88}{147}\right).$$  I found this example by using computer. I found the other examples, but I don't know there exist an infinite number of rational points in the equilateral triangle $ABC$. Then, here are my questions.  Question 1: Do there exist an infinite number of rational points in the equilateral triangle $ABC$ ?  Question 2: Can we find all rational points in the equilateral triangle $ABC$ ?


Time dependent workflow should not fire after criteria field changed

I've two field Date and a Picklist field Named Status with value;Active,Inactive,Pending.  I've written a time based workflow rule .  Evaluation Criteria: Evaluate the rule when a record is created, and any time it's edited to subsequently meet criteria.(because it should not fire after changing the other data)  Criteria: Status = Active  Action :fire email 1 hr before Date.  now when criteria matched, workflow fired and action will be in the Queue and it will fire at 1 hr before scheduled date. Its working fine.  The requirement is, when action will in queue and in mean time when I've changed the Status field to Inactive then action should not be fired. because record is not active.   Please suggest the workaround. thanks.


Why didn't the Ministry know what went on in the graveyard?

Harry and Cedric both had the trace. All three unforgivable curses were cast in their presence.  The trace tells you what spell is cast, where it's cast, and who is the presence of it.  We know this, because the Ministry knew that the Patronus charm was cast in the presence of Dudley.  How, exactly, did they not know Voldemort had returned, and killed Cedric?


Is there any clever method out there to make my executeEveryDayMethod() execute once a day, without having to involve the Windows TaskScheduler?


Why does a change of direction imply an acceleration?

We know that it takes no energy to change the direction of a vector, we know also that it takes no energy to displace a body in motion if a push is applied exactly at a right angle on its center of mass.  Considering that, if that is true, can you explain why a simple change of direction without any increase of speed is considered an acceleration?


Duplicate questions in feed, and questions incorrectly marked as unanswered

I see duplicate questions in the feed (Why is the book still wanted if Aida has memorized it?) and the question is marked as "unanswered" even though it has an upvoted answer.  I would expect unique questions in the feed, as well as questions with answers to not be marked as unanswered.   App Version: 1.6.3.4 Device: iPhone 6 OS Version: Version 10.2 (Build 14C92)


Long table starts in previous blank page

I am writing a longtable that spread across 2 pages. But LaTeX always adds starts the table in a new page rather than the previous blank page.  Now I want my longtable starts in the previous blank page (like the pictuer bellow), how can I do that? Thank you.    Here is my *.tex：  \documentclass[12pt]{article} \usepackage{longtable} \usepackage{lipsum}  \begin{document} \lipsum[1-3]  \begin{center} \begin{longtable}{|p{2cm}|p{10cm}|} \hline \textbf{First} & \textbf{Second entry}  \\ \hline \endfirsthead \hline \endhead \hline \endfoot \hline \endlastfoot  1   &   \lipsum[1]  \\ \hline  2   &   \lipsum[2]  \\ \hline \end{longtable} \end{center}  \end{document}


Increasing the h-size of plots in plt.subplot() inside a loop - Python

I have this code:  for i in ["Dia", "DiaSemana", "Mes", "Año", "Feriado"]:     plt.subplot(1,2,1)     sns.boxplot(x=i, y="Y", data=df)      plt.subplot(1,2,2)     sns.boxplot(x=i, y="Temp", data=df)      plt.tight_layout()     plt.show()   It gives me all the plots I need. Here is one-time loop:    As you can see, the x axis is overlapped and I'm trying to increase the horizontal size of each plot in order to have a better visualization.


How could I prove that $\Bbb Q({\sqrt2},{\sqrt3})$ and $\Bbb Q(2^\frac{1}{4}))$ aren't isomorphic? I need to prove it and I don't know how, but it seems easy. Thanks everybody.


About the property of $m$: if $n < m$ is co-prime to $m$, then $n$ is prime

The number $30$ has a curious property:  All numbers co-prime to it, which are between $1$ and $30$ (non-inclusive) are all prime numbers!  I tried searching(limited search, of course) for numbers $\gt 30$ that have this property, but could not find any.  Are there any such numbers $\gt 30$?


Inspired by this question  as well as many other similar questions asked here on Math SE. However, I could not prove it given my setup:  Suppose that $\mathcal T\subseteq\mathcal P(X)$ and $\mathfrak N:X\rightarrow\mathcal P(\mathcal P(X))$. Then it holds that   $\mathcal T$ is a topology over $X$ and for each $x\in X$ such that there exists a $O\in\mathcal T$ with $x\in O\subseteq N$ it holds that $N\in\mathfrak N$   if and only if   for each $x\in X$ it holds that   $\mathfrak N(x)$ is a filter over $X$, for each $N\in\mathfrak N(x)$ it holds that $x\in N$ and for each $N\in\mathfrak N(x)$ it holds that $\{z\in N:N\in\mathfrak N(z)\}\in\mathfrak N(x)$ and   $\mathcal T = \{O\subseteq X\mid\forall x\in X:O\in\mathfrak N(x)\}$.   $$\\$$ In other words:   $\mathcal T$ is a topology over $X$ and $N$ is a $\mathcal T$-neighborhood for $x\in X$ (i.e. $N\in\mathfrak N(x)$) iff there exists a $O\in\mathcal T$ such that $x\in O\subseteq N$   if and only if   for each $x\in X$ it holds that   $\mathfrak N(x)$ is a filter over $X$, for each $N\in\mathfrak N(x)$ it holds that $x\in N$ and for each $N\in\mathfrak N(x)$ it holds that $\{z\in N:N\in\mathfrak N(z)\}\in\mathfrak N(x)$  $O\subseteq X$ is $\mathfrak N$-open (i.e. $O\in\mathcal T$) iff for each $x\in O$ it holds that $O\in\mathfrak N(x)$   The other questions could help me figuring out the importance and meaning of the respective axioms. Proving the equivalence is hard for me though. I have proved the "$\Rightarrow$"-direction except for "for each $N\in\mathfrak N(x)$ it holds that $\{z\in N:N\in\mathfrak N(z)\}\in\mathfrak N(x)$". Any hints?


What happens with votes cast with rep < 15 exactly?

On many stackexchange sites I haven't enough reputation to cast an up-vote. Always I get the message "Thanks for the feedback! Votes cast by those with less than 15 reputation are recorded, but do not change the publicly displayed post score".  What does recorded mean exactly?    Can the owner of the up-voted question/answer see in any kind, that he/she got my up-vote? Does he/she get rep for this? What happens with these votes, if I reach the 15 rep? Will they take effect subsequently? Or are they just recorded for my "vote-history"?


How can a non-operator player run this command by clicking on a clickable tellraw text in 1.13+?

My command is something simple: /tellraw @a {"text":"Test","clickEvent":{"action":"run_command","value":"/scoreboard players add Jimmy test 1"}} The issue is that if a non-operator clicks on this text the command will not run. This question was asked for 1.12, but the /trigger command was removed, meaning those answers don't apply to the answer for this question. So, in 1.13+ Minecraft, how can I get around non-operators being unable to use the clickable text?


Returning the MD5-hash of all files in a directory to a .txt file with file name

I have a directory of pictures.  I need the MD5-hash of each file in that directory and the name of the file placed into a .txt document. This file is to be read at a later time to reference the MD5 and file name together.  Note: I would like this to just pull all directory files with me specifying them. I have tried playing with tar and find and I just cannot seem to find a good solution...  This is a directory example:  /Desktop/testing RandomFilename1.png RandomFilename2.png RandomFilename3.png   The .txt output is:  RandomFilename1,da39a3ee5e6b4b0d3255bfef95601890afd80709 RandomFilename2,da39a3ee5e6b4b0d3255bfef95601890afd80709 RandomFilename3,da39a3ee5e6b4b0d3255bfef95601890afd80709   I've looked everywhere online with no luck. This will be on a Linux terminal.


Ubuntu Phone Aquaris 4.5 today screen does not automatically change

I have a new Ubuntu Aquaris E4.5 phone (latest updates installed).  Locale UK Timzone British Summer Time.  The Today Scope screen does not automatically change days, so for example today is Thursday, but this morning is was still showing Wednesday.  The only way I could seem to get it to change was to reboot the phone.  Is this a bug? or have I done something wrong?


Absolute and relative polar coordinates in pgfplots

Today i encountered some weird behaviour (lines with off angles and wrong lengths) while creating graphics with TikZ/PGF. After some searching i have narrowed down the problem to the example shown below:  Here i am trying to create a line of length 10 that starts at (0/0) and has a 30° slope using polar coordinates.  \documentclass[11pt]{scrreprt}  \usepackage{tikz} \usepackage{pgfplots} \pgfplotsset{compat=1.15}  \begin{document} \begin{figure}[h]     \begin{tikzpicture}         \begin{axis} [             axis lines=center,             xlabel={$x$},             ylabel={$y$},             ymin=-1.5, ymax=15.5,             xmin=-1.5, xmax=20.5,             grid=major         ]             \draw [blue] (0,0) -- ++(30:10);             \draw [green] (0,0) -- (30:10);             \draw (0,0) circle [radius=10];         \end{axis}     \end{tikzpicture} \end{figure}  \end{document}     To my mind, the blue and the green line should be identical, but for some reason that i cannot explain, they are not.  Here is how i understand it:  The only difference between the two commands  \draw [blue] (0,0) -- ++(30:10); \draw [green] (0,0) -- (30:10);   is that the first uses relative coordinates and the second does not. But since the first command uses the last part of the path as its point of reference (0/0) and the second command uses the origin of the coordinate system as its point of reference (0/0) [TikZ/PGF manual, section 13.2.1] there should be no difference.  Since my prediction of what should happen does not match with reality, obviously i am missing something. I would be glad if somebody could give me a hint as to what it is that i don't understand here.  Thanks.


Is there a Python library function which attempts to guess the character-encoding of some bytes?

I'm writing some mail-processing software in Python that is encountering strange bytes in header fields.  I suspect this is just malformed mail; the message itself claims to be us-ascii, so I don't think there is a true encoding, but I'd like to get out a unicode string approximating the original one without throwing a UnicodeDecodeError.  So, I'm looking for a function that takes a str and optionally some hints and does its darndest to give me back a unicode.  I could write one of course, but if such a function exists its author has probably thought a bit deeper about the best way to go about this.  I also know that Python's design prefers explicit to implicit and that the standard library is designed to avoid implicit magic in decoding text. I just want to explicitly say "go ahead and guess".


What is the most frequent concurrency issue you've encountered in Java?

This is a poll of sorts about common concurrency problems in Java.  An example might be the classic deadlock or race condition or perhaps EDT threading bugs in Swing.  I'm interested both in a breadth of possible issues but also in what issues are most common.  So, please leave one specific answer of a Java concurrency bug per comment and vote up if you see one you've encountered.


How to solve the limit:$ \lim_{x \to 0,y \to 0} \frac{x^2y^2}{x^3+y^3} $

I confronted a problem, that is  $$ \lim_{x \to 0,y \to 0} \frac{x^2y^2}{x^3+y^3} $$  I tried to use $x=r\cos(\theta) , y=r\sin(\theta)$ to solve the problem, and I got  $$\lim_{r \to 0}r(\frac{\cos^2(\theta)\sin^2(\theta)}{\cos^3(\theta)+\sin^3(\theta)})$$ And no matter what value $\theta$ takes, we all have the limit is zero.  My question is: (1) Am I right? Or (2) If we can change the limit into such "$rf(\theta)$" form, when r goes to zero, will the limit go to zero?


Why is there a percent sign '%' in the IPv6 address?

I am using the .NET Framework classes to get the IP addresses for my machine.   Dns.GetHostAddresses(Dns.GetHostName())   I have a VirtualBox adapter which has both an IPv4 and IPv6 address. Using the .NET code I am getting the IPv6 address as fe80::71a3:2b00:ddd3:753f%16   Notice the %16 at the end?    However, if I query the same using WMI, I am getting the address as 'fe80::71a3:2b00:ddd3:753f'  So, does the %16 have any special significance?   Edit:   I just had some more observations about this. And they match pretty well with what Stephen Jennings said in his answer.   I installed Vmware to see what IPv6 address it issued. The addresses were :  fe80::3dd0:7f8e:57b7:34d5%19  fe80::b059:65f4:e877:c40%20  Clearly, the numbers after % are not some hex representation. I checked all the properties available for a network adapter using Wmi and found that the numbers are exactly same as the InterfaceIndex property of each network adapter. As per , it uniquely identifies each network adapter and this property was introduced in Vista.   What still confused me was why would the IPAddress class allow you to create an ip address in that format unless it was valid. The answer was provided by Stephen. The number is the scope id. IPAddress has a constructor that accepts the address AND a scope id.   Oh, and all these three network adapters were link local. Confirmed it via ipconfig  Cool. That was interesting!!


How to change the format of a cell without changing its content in Ms. Excel?

I want to change a number of cells formatted for date to text format, but unable to do so. For example, one cell contains 29/01/2018. When I changed the format to text, its changed to 43129. The question is : How to change the format, but retain the original content of the cell?  Any help would be appreciated


Why didn't Dumbledore use Harry's memory to investigate Cedric Diggory's death?

explains why the Ministry didn't look into the death, but it doesn't explain why Dumbledore didn't collect any evidence to disprove the official story or to aid in his fight against Voldemort. The most obvious path would be to extract Harry's memory of Cedric's death during the scene where Harry tells him what happened in the graveyard. This has the following clear advantages:  Dumbledore gets very good intel on Voldemort's means of resurrection. This solves much of the plot of book six two books early.  It's good intel on what Death Eaters are and aren't active, including any new and unknown ones. Knowing what your masked enemy looks and sounds like is always good and it's yet more evidence against previously trialed and cleared Death Eaters. For all Dumbledore knows, there could've been something really helpful like an unknown new nine-legged Death Eater.  The memory would've showed an accurate depiction of very dark magic. As it is very unlikely that Harry knows of this magic (and memory-tampering tends to be obvious), it gives strong evidence that what he saw wasn't a delusion. Even with , it immediately puts a massive hole in Fudge's explanation that Harry is insane.  Dark magic leaves traces. The memory gives the location of the resurrection and therefore a very good place to investigate. Again, this would give evidence that Harry is not delusional.  It's plain and simply more evidence that Voldemort is back.   So, why didn't Dumbledore do it? Even if he didn't think it would persuade Fudge, I've given at least three good reasons why he should look anyway.


Why my function for reversing a string prints out each element from a new line in Python?

I'm pretty new to python and curious why my function prints out each character from a new line. Any suggestions on how to correct it? Any other implementations of that would be helpful as well.   This how my function looks like  def reverse(word):     len_word = len(word)     x = 0     while x < len_word:         x += 1         index = len_word - x          print(word[index]) reverse("123abcd")    What I get is the input with each character on a new line.  What I want to get: dcba321


I am using the maven assembly plugin to build a single JAR but I'm getting this error after running the following  java -jar target/pdfbox-printing-1.0-SNAPSHOT-jar-with-dependencies.jar   the error is   Exception in thread "main" java.lang.NoClassDefFoundError: org/bouncycastle/jce/provider/BouncyCastleProvider   this is how i compile the JAR  mvn clean compile assembly:single   here is my pom.xml  <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">   <modelVersion>4.0.0</modelVersion>   <groupId>com.company.printing</groupId>   <artifactId>pdfbox-printing</artifactId>   <packaging>jar</packaging>   <version>1.0-SNAPSHOT</version>   <name>pdfbox-printing</name>   <url>http://maven.apache.org</url>   <dependencies>     <dependency>       <groupId>junit</groupId>       <artifactId>junit</artifactId>       <version>3.8.1</version>       <scope>test</scope>     </dependency>     <dependency>       <groupId>org.apache.pdfbox</groupId>       <artifactId>pdfbox</artifactId>       <version>2.0.0</version>     </dependency>   </dependencies>   <build>     <plugins>       <plugin>         <artifactId>maven-assembly-plugin</artifactId>         <executions>           <execution>             <phase>package</phase>             <goals>               <goal>single</goal>             </goals>           </execution>         </executions>         <configuration>           <archive>             <manifest>               <mainClass>com.company.printing.App</mainClass>             </manifest>           </archive>           <descriptorRefs>             <descriptorRef>jar-with-dependencies</descriptorRef>           </descriptorRefs>         </configuration>       </plugin>     </plugins>   </build> </project>   i am actually trying to build a project that uses apache pdfbox. and i thought the maven assembly plugin will bundle all the dependencies in one JAR but why am i getting this error if its true.


Disfunctionality of super key in ubuntu 20.04

I recently installed Ubuntu 20.04 and super key not working properly. When i enable dash to dock gnome extension, sometimes super key doesn't work and i have to reset gnome. When i press super key button to see activities for example. Any idea?  UPDATE: Sometimes another dock overlaying existing dock.


Integral of the square of the normal distribution.

Does someone know what the integral of the square of the normal distribution with standard deviation sigma over the range $-\infty$ to $+\infty$ is?  Thanks!


Q: How to proof there is $x\in \Bbb Z$ such as $gcd (ax+b,c)=1$ if (a,b)=1

the question have two parts let $a,b,c\in \Bbb Z$ such as $gcd(a,b)=1$ and $c\neq0$ Proof: a)There are $x,y\in \Bbb Z$ such as $gcd(ax+by,c)=1$ b)There is $x\in \Bbb Z$ such as $gcd (ax+b,c)=1$ Answer: a) If $gcd(a,b)=1$ then there are exists $x,y\in \Bbb Z$ such as $ax+by=1$ thus we will choose the exact ones, therefore $$gcd(ax+by,c)=gcd(1,c)=1$$ b) I guess it's use the proof before I'm not quite sure. thank you for helping.


Here is the problem, i tried to install phoenix os by this tutorial:   and so i created a 30gb .img in /phoenix folder later i decided to delete it, so i deleted the /phoenix folder by moving to trash can and then empty the trash can. The problem is that in Disks they say me that my Ubuntu partition has that 30gb in use. ¿How can i free this space? (sorry my bad english please)


I was watching a video by Blender Guru and noticed that corners in his scene have shadows in the Solid View. However, my corners do not have shadows like he does. Is this an setting I can turn on in Blender? If so, how can I turn it on?


How can I easily animate cutaway views on multiple objects?

I'm trying to create animated  on multiple objects in my scene. For example, in my car model, the seats and other interior objects are separate objects.    talks about using an animated bisecting technique. However, it involves adding a solidify and boolean modifier to every object.  Is there an easier solution?


Now I’d like to present you guys, the trailer of the movie.   Vs     Now I’d like to present to you guys, the trailer of the movie.   Also,      This is the last letter she sent me.    Vs      This is the last letter she sent to me.    Is to required? Or is it not?


Is there a ping command in python that returns a different value if a host is up, or if a host is down?

I am trying to create a utility to visualize if a set of IPs in my local network are up using python. I stumbled into a problem right away, because my plan was to use something like:  isup=os.system("ping IP")   And than depending on the value of isup I would either display that the host is online, or offline, but no matter which it is, only 0 is constantly being returned. I am using win7, and I would like to do this in python. Any help is highly appreciated!  Edit: Please stop flagging this as a duplicate, the solutions in that question are either for Linux or python 2.x.


If an enemy is just below a 10-foot-high ceiling, are they in melee range of a creature on the ground?

We encountered a Vampire Spawn in the 10-foot-high basement of an old church. The first strike was mine, after which the creature attacked my ally and retreated onto the ceiling as the thundering roar of my Booming Blade punished its retreat. Still inexperienced and unsure about my reach, after a short consultation with my mind, I decided to spend my turn switching to my trusty crossbow and make some distance.  However this turned out to be a mistake, since right after, the creature was in in my face trying to gouge out my eyes. Due to my nimbleness I managed to avoid its attacks. Regretting my earlier choice to change weapons I was left with the options to switch weapons and miss another turn, attack with disadvantage, or use my crossbow as an improvised melee weapon and trust in Booming Blade to hold the enemy in place after I disengaged.  Perhaps I should have switched weapons, but I decided that 1d4 (improvised weapon) + 1 (magic ring) + 1d8 (booming blade) was good enough. I missed.  On the plus side, it was my crossbow's sneak attack assisted bolt that finally slayed the Vampire by piercing its heart.    In this situation, would it have been possible to just attack upwards instead of changing to the crossbow?  In session, this was something to be looked up later and decided against, but I haven't found any rules on attacking in 3D.  With me being more than 5 feet in height and my melee attack range considered to be 5 feet, I should have been able to reach the ceiling itself, not to mention the Vampire Spawn hanging from it.    As for exact measurements (read this part only if you enjoy pointlessly over-analyzing things):  My character is 5 feet 6 inches/5.5 feet, which gives an  (for a human, my character is a Kenku), . This should give me a height of 8.3 to 8.9 feet from standing statically.    Testing it in real life, my estimated and standing reach match to less than 0.2 inches of the estimation on the site and I'm just shy of reaching my ceiling standing statically. As a test I tried moving as if I was attacking my ceiling and based on where I could feel my hand touch the ceiling, the length of my fingers and how much distance I lacked to reach my ceiling, I estimate about 0.4 feet in additional height. Considering that I'm taller than my character, let's say that gives 0.3 feet, increasing the height to 8.6 - 9.2 feet and that's still without changing how you hold the handle of the sword. In addition, just lying on the ground, my torso and legs measure about 0.6 feet.  Because my Kenku isn't a human, only a humanoid, it's impossible to estimate arm length which influences standing reach, however, considering that birds usually have a high wingspan and long legs, I think it's reasonable to assume that the arms should be as long, if not longer than, a human's.    So that would require the Vampire Spawn to be flat against the ceiling without any parts hanging down more than 0.2 to 0.8 feet for it to be outside of my reach. I consider that unlikely.  What are the actual rules for this type of scenario, or how do you handle it in your group? Should I be allowed to melee attack an enemy that's on a ceiling or low in the air?


A few months ago, I had Windows 8 as the only operative system on my computer and I wanted to install Ubuntu, having both operative systems on my pc (dual boot). However, after supposedly installing Ubuntu, I wanted both Ubuntu and Windows 8 to appear on the screen when booting (so I could choose which one I wanted to work with), and that's when the problem appeared. In the terminal, I followed a tutorial that could make the dual boot work (I don't remember what I wrote) and, all of a sudden, all of my partitions were gone. I initiated the computer again and it would go straight to the BIOS. Then, after several tries, I somehow installed Ubuntu and have been working on it since. However, I know that all of my partitions are messed up and now that I need both Windows and Ubuntu on my pc, I really need to figure this out. I really appreciate any help that you can give.  Here's a print screen of gparted   which shows all of the partitions on the computer.


Let's say there's a series of the form $$S=\frac{1}{10^2}+\frac{1\cdot3}{1\cdot2\cdot10^4}+\frac{1\cdot3\cdot5}{1\cdot2\cdot3\cdot10^6}+...$$ Now i had written the rth term as $$T_r=\frac{1\cdot3\cdot5....(2r-1)}{1\cdot2\cdot3.... r\cdot10^{2r}}=\frac{2r!}{r!\cdot r!\cdot2^r\cdot10^{2r}}$$ I came to the second equivalence by mutliplying and dividing the first expression with $2\cdot4\cdot6....2r\;$and then taking out a power of 2 from each of the even numbers multiplied in the denomininator.  From the looks of it, these expressions tend to give the idea of being solved using binomial most probably the expansion for negative indices but I don't understand how to get to the result from here


Unity: How to get a GameObject programmatically?

I have created a prefab. In Unity Scene editor, I dragged the prefab into the scene and named it PrefabA (this is a GameObject instance of the Prefab).  Now, I need to update the PrefabA position. How can I access the GameObject "PrefabA" during runtime via script?     GameObject prefab =  GameObject.Find("Canvas/PrefabA").GetComponent<GameObject>();   The code above throws Object reference not set to an instance of an object.


Why does Java skip over parts of this If statement

I have made a dropdown menu where you can choose if you want to play against a friend or against the computer, and this is were I run into problems.  The program skips over a part of the if statement, and goes to the else statement further below and I do not know why? They are basically the same.  I wanted to check if it would run if I clicked the PVC option, so I made it print out hello when it comes to that, and it does, but it just skips over the rest of the statement after the for loop. It is supposed to set the buttons to X and ÅO, but goes to the normal version where it gets set to X and O instead.  PVC:  if (menu.get(1).equals(e.getSource())) {      System.out.println("hello");     for (int i = 0; i < 9; i++) {         score.set(i,0);         knapper.get(i).setText(" ");         count=1;         Gamechoice=true;     }      for (int i = 0; i < 9; i++) {         if (knapper.get(i).equals(e.getSource())) {             count += 1;              if (count % 2 == 0) {                 if (knapper.get(i).getText() == "X" || knapper.get(i).getText() == "O") {                     System.out.println("Button allready pressed");                 } else {                     System.out.println("Pressed " + (i + 1));                      System.out.println(e.getSource());                     knapper.get(i).setText("X");                     score.set(i, 1);                 }             } else if (count % 2 != 0) {                  if (knapper.get(i).getText() == "X" || knapper.get(i).getText() == "O") {                     System.out.println("Button allready pressed");                 } else {                     System.out.println(e.getSource());                     knapper.get(i).setText("ÅO");                     score.set(i, -1);                 }             }         }     } } else{     for (int i = 0; i < 9; i++) {         if (knapper.get(i).equals(e.getSource())) {             count += 1;              if (count % 2 == 0) {                 if (knapper.get(i).getText() == "X" || knapper.get(i).getText() == "O") {                     System.out.println("Button allready pressed");                 } else {                     System.out.println("Pressed " + (i + 1));                      System.out.println(e.getSource());                     knapper.get(i).setText("X");                     score.set(i, 1);                 }             } else if (count % 2 != 0) {                 if (knapper.get(i).getText() == "X" || knapper.get(i).getText() == "O") {                     System.out.println("Button allready pressed");                 } else {                     System.out.println(e.getSource());                     knapper.get(i).setText("O");                     score.set(i, -1);                 }             }         }     } }


Wobbly windows plugin not working in 17.10

I have recently upgraded from 17.04 to 17.10.   Upon upgrading, I noticed the "wobbly windows" feature wasn't working anymore.  I opened the CompizConfig settings manager and the feature was active.   I tried to disable and re-enable with no effect.   I am not knowledgeable enough to figure out whether any of the detailed settings might be the problem - here is a screenshot of what my settings for wobbly windows look like:    Note: I have tried disabling all other effects, with no change.


Format a enumerate environment like a tabular

NOTE: The point is not to modify the enumerate environment. I need to convert it to the tabular like environment automatically.  I would like to format an enumerate environment of 4 items  \begin{enumerate} \item Fist point \item Second point \item Third point \item Fourth point \end{enumerate}   like a tabular environment. The output should be similar to the output of  \begin{tabular}{@{}rr@{}} a) Fist point  & b) Second point \\ c) Third point & d) Fourth point \\ \end{tabular}   My first thought was to use inline lists, but this would not assure that items b) and d) are aligned.   I'm sorry for not having yet a MWE, but I am looking more for ideas to start playing with that a full answer. I will edit the question when I have something more concrete.


Why don't we develop immunity against common cold?

We all suffer from common cold, and that, frequently. Why have we not developed immunity against it till now? By immunity I mean immunity as a species.


Why isn't the date visible on the top bar?

The day of the week time is displayed on the top bar... Why isn't the date displayed there, like it was in previous versions??? Why on earth would this capability have been removed???


Is there the regular expression that can completely remove a HTML tag?  By the way, I'm using Java.


Identifying a thin, black, worm-like creature with a hammer-shaped head

I came across the creature shown in the photo below yesterday evening while walking the dogs. At first, I thought it was an earthworm, but a flashlight revealed it to be something I had never seen before.    It is approximately 12 inches (300 mm) in length and about 1/3 of an inch (10 mm) in diameter at its maximum. It is pitch black and very shiny—like piano black. It moves very slowly, using a snake-like motion. It had a very strange head, like a hammerhead shark.  I live in Durban, South Africa, if that helps to narrow down the possibilities.  Can anyone help in identifying this creature?


Why was the existential quantifier symbol ∃ based off of an inverted "E"?

Peano introduced a number of logical symbols still used today:   ∨ (from Latin vel) ∧ (inverted ∨) ∃   This inversion of Latin letters as symbols (and inversion of symbols to signify their 'opposite' operation) was followed by later logicians:   ∀ (Gentzen, : inverted A from "All-Zeichen", by analogy to ∃) ⊥ (inverted ⊤)   I had always assumed that ∃ stood for "E" in "Existential" / "there Exists", but Peano wrote and introduced this symbol in French, not using any words beginning 'E':     Mais nous préférons l'indiquer par la nouvelle notation      Ǝa      qu'on peut lire « il y a des a ».         , Peano (1897)      So why did he choose an inverted "E"?


How to synchronize systemd stop order from one service?

Suppose I have a.service which I cannot modify, and b.service which I can modify, I want to see this stop order:  Stopping b.service ... Stopped b.service Stopping a.service ... Stopped a.service   instead of this:  Stopping b.service ... Stopping a.service ... Stopped b.service Stopped a.service   Assume that b.service may take at least 20 seconds to finish.


Compartmentalized Building using Scripts

I'm considering learning blender as my first foray into animation. Before I commit to learning it, however, I would like to know if the Blender workflow will lend itself to efficiently complete the tasks I have in mind. To illustrate what functionality I'm looking for, say you created a TV Series that revolves around a girl. Say that in episode 70, I decide I want her father to die for some reason. Perhaps she remembers then that her father was always saying she should read a particular book, but she never did. And now she wants to. When creating episode 1, I didn't know that I would have episode 70 play out in this way. Now, I'd like to go back and change the girl's bookshelf to include a book that stands out so as to foreshadow that it may be important in the future. If I was doing all this in blender, would I have to go back through all of the episodes separately and change the bookshelf manually? My hope would be that the construction of the girl's room could be written into a separate script, so that each episode sources it and builds the room. Therefore, I could change that one source script, and every episode gets updated at once. Does Blender have this sort of functionality? Or is there some other software that is more suitable? I imagine that animated TV shows have addressed this sort of issue already, how have they done it?


I'm on Xubuntu 11.10 and currently trying to use emblems in Thunar to mark which videos in a folder I've already watched.  The problem is I can't find any terminal command to do so and neither can I change the properties of multiple files in Thunar as the context menu item 'properties' is greyed out as soon as I select more than one file.  The command 'gvfs-set-attribute' which works with Nautilus doesn't do anything in Thunar. I guess Thunar stores the meta-data in some other way.  Can anyone tell me how to either set the emblems with a custom command (better solution) or change multiple file properties in Thunar?


DnD 4e Books to get (errata? where to get?)

I have the DnD 4e red box, and some friends and I are keen to play more.  I live in Belgium (Europe) and finding your gear here isn't all that easy. Most of the books sold online come from America.  Which books should I get? First I thought I'd get the 3 core rulebooks, but now I see that there's alot (even game changing) errata. I also notice that there are different ways to get all your rules, some speak of buying 2 essential books and the compendium... I want to play the game, with quite some content, what is the way to go? Anyone that can point me out a good site that has these things for me?  (Then I also noticed that there are things like Players Handbook 2 etc. These are not updated version but expansions I presume?)  Thanks!


Why can I only change my Stack Overflow name once every 30 days?

I have a  on Stack Overflow. I recently decided to change the name on my profile. I did this, but I made a spelling mistake! I wrote "Kryton" instead of "Kryten"! When I tried to fix this, a message came back saying that I can only change my profile name every 30 days. Why? Is there any way I can fix my profile name?


You are throwing n balls into m bins randomly.   What is the probability to be empty of the first $k$ bin? Given $k$ bins are empty. What is the probability to be empty of $(k+1)th$ bin? Forget the first 2 cases, let throw balls into $m - k$ bins. What is the probability to be empty of the first bin?   Thank you


When is damage considered to have "killed a creature"?

The Narzugon's Hellfire Lance states:     Hellfire Lance. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 11 (1d12 + 5) piercing damage plus 16 (3d10) fire damage. If this damage kills a creature, the creature's soul rises from the River Styx as a lemure in Avernus in 1d4 hours. If the creature isn't revived before then, only a wish spell or killing the lemure and casting true resurrection on the creature's original body can restore it to life. Constructs and devils are immune to this effect.   Notably, this wording is different from "if this damage reduces a creature to 0 hit points" effects.   When is the Lance's damage considered to have "killed a creature"?  A few situations I can think of (intended as illustrative examples of boundary cases, I'm not expecting an answer to address all of these):   If the lance's damage renders the creature unconscious, and they then fail 3 death saves without taking further damage If the lance causes a creature to fail its last death save If something other than the lance's damage rendered a creature unconscious, but then an attack from the lance causes the creature to fail 1-2 death saves, and they fail the last one naturally If the lance's damage rendered a creature unconscious, but then damage from another source causes the creature to fail two death saves, and they fail the last one naturally If the lance caused massive damage to a creature, killing them instantly


When I select another object and transform it the Sapling tree generator panel is gone. I can't get it back when I reselect the tree. Is it possible at all to have the panel back?


How can it be that the sun emits more than a black body?

As far as I know, a black body is an ideal emitter. So how can it be that a non-ideal emitter emits more radiation than a black body?  This happens only in a very limited area at around 500nm, but it still happens: it looks like at the maximum it is around 15% above black body.  This seems impossibile for my understand of a black body. Especially because just for that there is the emissivity value ε, or better ε(λ)      Quantitatively, emissivity is the ratio of the thermal radiation from a surface to the radiation from an ideal black surface at the same temperature. The ratio varies from 0 to 1    Means 0 ≤ ε(λ) ≤ 1    What is the right interpretation? What is the sun doing there, seems like ε(500nm)=1.15?


Please any body say How to install windows 7 on ubuntu 14.04 dual boot would be a Big help if explained in Step by step !!


Font style on the second page of Sandbox Archive is broken for mobile web

Compare the font style in the footer of the 1st and  of Sandbox Archive in mobile web:                Arrows in page selector are also affected.


Set Theoretic Explanation of Existence of Convergent Sequence

Suppose that we have some set $A \subseteq \mathbb R$ whose infimum is $m$. Now, generally, we simply say that in such a situation, there is a sequence $\{a_n\}_{n \in \mathbb N} \subseteq A$ which converges to $m$. However, is there a way to prove this statement with ZF axioms? I want to say that with ZFC, we should use Axiom of Choice to give a function $f: \mathbb N \mapsto a_n$ with $a_n \in A \cap B_{1/n}(m)$ where $B_\epsilon(a)$ is the $\epsilon$-ball around $a$. This certainly suffices, but presentation of mathematics generally distinguishes proofs which require the Axiom of Choice versus those which don't, so I'm thinking I might be overlooking a proof which uses only ZF.


Prove that the points $a_1,a_2,a_3$ are vertices of an equilateral triangle if and only if $a_1^2+a_2^2+a_3^2=a_1a_2+a_2a_3+a_3a_1$.   I rewrite the equation as $2a_1^2+2a_2^2+2a_3^2-2a_1a_2-2a_2a_3-2a_3a_1=0$, which is $(a_1-a_2)^2+(a_2-a_3)^2+(a_3-a_1)^2=0$. This looks quite nice, but I'm not sure how to relate it to the equilateral triangle.


[SQL Server]Incorrect syntax near 'neal'

I'm trying to update my a row. But it automatically creates an error because the data in a column contains this Shaquille O'neal Or are there any problems ?  Here's my code    <?php if(isset($_POST['editSubmit'])){     $buildingID       = $_POST['editBuilding'];     $buildingName     = $_POST['editBuildingName'];        $buildingProject  = $_POST['editBuildingProject'];     $buildingFloors   = $_POST['editBuildingFloors'];     $q = "update tblBuilding SET buildingName= '$buildingName' building_projectID='$buildingProject'           floorNumber = '$buildingFloors'                    where buildingID = '$buildingID'";      $query = $db-> prepare($q);     $results = $query->execute();     echo" <meta http-equiv='refresh' content='0;url=project.php'>";  } ?>   EDITED: Prepared:  <?php if(isset($_POST['editSubmit'])){     $buildingID       = $_POST['editBuilding'];     $buildingName     = $_POST['editBuildingName'];        $buildingProject  = $_POST['editBuildingProject'];     $buildingFloors   = $_POST['editBuildingFloors'];  $stmt = $db->prepare("update tblBuilding set buildingName=?, building_projectID=?,floorNumber=?  where buildingID = $buildingID");  $stmt->bindParam(1, $buildingName ); $stmt->bindParam(2, $buildingProject); $stmt->bindParam(3, $buildingFloors ); $stmt->execute();        echo" <meta http-equiv='refresh' content='0;url=project.php'>";  } ?>


Are there any reasons to use the identity link in logistic regression (or any other glm)?

From this , the following statement is posed: 'Though not "wrong", you'd want a good reason for using an identity link to model a Bernoulli probability.'  I would like to know what good reasons would result in an identity link being used for logistic regression, if these exist. Do these reasons generalise to GLMs?


How many subsspaces and how calculate them in a Subspace

Let $n>0$. Let $V\subset \mathbb{F}_2^n$ a vectorial space. Let $U$ a subspace of $V$.  How many subspaces $W_i \subset V$, at most, I can describe (for example using the basis) such that $U \subset W_i$?


Find a function $f$ such that $\lim_{x\to{}0}{f(x^2)}$ exists, but $ \lim_{x\to{}0}{f(x)}$ does not.

Context: I'm brushing up on some Analysis and currently going the exercises in M. Spivak's Calculus book, specifically chapter 5 on limits. Everything was going fine until I came across this question. I've been thinking about it for some time with no luck. Question: "Give an example where $\lim_{x\to{}0}{f(x^2)}$ exists, but  $\lim_{x\to{}0}{f(x)}$ does not." My attempts: A previous question showed that $\lim_{x\to{}0}{f(x^3)}=\lim_{x\to{}0}{f(x)}$, which I believe works because we can find the third root of any real number (which was useful in the epsilon - delta proof for it). Which makes me believe the above fails because we can't square root negative reals. This lead me to play around with functions involving $\sqrt{x}$ and utilising its 'undefinedness' on the negatives. I started with $f(x)=\sqrt{x-1}$ which clearly has an undefined limit at $0$. But this is of course no different (considering the limit at $0$ that is) to $f(x^2)$. Any hints? I feel as though I'm overlooking something so simple.


If $x^2=e \forall x \in \ G$ why does that imply that $ |G|=2^n$ (for some natural $n$) ? I get from Lagrange's Theorem that $2$ divides $|G|$.


Is the correct usage of the non-taxable or nontaxable? I'm not sure what the correct use is. I want to say that it is with the hyphen however it ha become a debate that this could be incorrect.


Do you "watch" a movie or "see" a movie?

Which of the following verbs is most commonly used with movie? Or are they both used, but the connotations are different?  I watched a good movie yesterday. I saw a good movie yesterday.


How to remove all files in a directory except one file in Solaris

I have a directory icontaining a large number of files. I want to delete all files except for file.txt in Solaris. How do I do this?   I tried doing -->  rm !(UsageRequest.csv)  But it didn't worked. Solaris is throwing error as "Unexpected Token - '('  ".


How is it possible to assign a material directly to an object using the python api, i.e. to use the same mesh linked to these object but a different material? If I use the method obj.data.materials.new() the material is linked to the mesh and the obj.material_slots property is read only. Has someone some advice how to accomplish that? Thanks in advance.


I'm studing classical physics and i'm stuck with the simple pressure formula defined as:  $P=\frac{dF_{\perp }}{dS}$  Now, i know some calculus and the concept of infinitesimal in physics; however what i dont understand is :  according with the fact that $dF_{\perp }$ represent an infinitesimal change, it's an infinitesimal change from which quantity ?


Do I need to use 'in' or 'with' in the following sentence?  'Some images, like the ones of the wounded civilian, have been shot up close, making you feel more involved in/with what they show.'  Thanks


Who were the aliens seen in this scene from The Phantom Menace (alongside the ET species)?

In the image below, we can see ET's species at the bottom left. Is the species at the top right of the image known in Star Wars lore?


Is there any certain chronological order of all of Isaac Asimov's series, novels and short stories that Isaac Asimov himself specified?

Even though that there are many recommended personal reading orders about Isaac Asimov's series, novels and short stories, is there any specific chronological order which was specified by Isaac Asimov about his books?


Is it okay to delete the ~/.cache folder?

When I use disk usage analyzer and scan my home folder, the .cache folder in my home directory always shows up with a decent bit of things in it.   Would it be okay for me to delete the contents of this folder or would it damage something?


Why am I getting this screen all of a sudden when I turn my Laptop on?

I'm not even sure what or how to Google this. I'm getting this error on a black screen when I power on my laptop and select Ubuntu from the grub menu. I'm running Linux 18.04 LTS on a dual-booted machine (ASUS). The Linux is on an external hard disk (sdb). Windows 10 is on sda T.SE4585) tpm_crb MSFT0101:00: [Firmware Bug): ACFI region dnes t saer ntire command./response buffer. [mem 0xfed40000-0xfed4087f f1Ag ÚGE1) ve fe.964599) tpm_crb MSF TO101:00: [Firmware Bug]: ACPI region does not coVEr E Pntire tommand/response buffer. [mem 0xfed40000-0xfed4087f flag T1] ve fe2.424212] sd 2:0:0:0: [sdb) No Caching mode page found 2.424257] sd 2:0:0:0: [sdb) ASsuming drive cache: write through 2.428540] scsi 2:0:0:1: Wrong diagnostic page; asked for 1 got 8 2.428566] scsi 2:0:0:1: Failed to get diagnostic page 0x1 2.428586] scsi 2:0:0:1: Failed to bind enclosure -19dev/sdb2: Superblock needs_recovery flag is clear, but journal has data. dev/sdb2: Run journal anyway/dev/sdb2: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY. (i.e., without -a or -p options)fsck exited with status code 4 The root filesystem on /dev/sdb2 requires a manual fsckBusyBox v1.27.2 (Ubuntu 1:1.27.2-2ubuntu3.2) built-in shell (ash) Enter 'help' for a list of built-in commands.(initramfs)


I have a class that extends bpy.types.Panel. When a combination of items are chosen in another panel, I want this panel to appear, but not otherwise. Right now the panel will always show after being registered. I browsed through the documentation and found nothing useful. What function can I call or flag can I set to show and hide a panel, say, on clicking a button?


I can't use my Google Account password to bypass the lock screen

On my CM9 / ICS 4.0 phone, if I incorrectly enter the drawn pattern five times in a row, it locks itself for 30 seconds. I can't enter any more passwords, but I can click a "forgot my password" button and enter my Google Account password.  On my rooted 4.0.3 tablet running a custom ROM, my lock screen is set with a numeric PIN. If I input it incorrectly five times or more, it locks itself and I can't enter any more passwords.   I'm not offered the option to enter my google account password to bypass this, although I have configured a Google account on the device.  I want to activate the "I forgot" button in order to enter my Google Account credentials. Is it possible?


Please help me find the author/title of this book

WARNING: Graphic  All I remember about this fantasy horror book is the following:  There is a killer that can stop time. He is searching (or chasing) the protagonist. There is one graphic sequence, where the killer stops time, and is going after the main hero, and the world around them is frozen - they move past frozen people, and the killer rips off their limbs and such (I think there is also reference to how much pain they will feel once they "wake" up).  I was reading S.K and Koontz at the time, but I don't know if it was either of them. I think the book had the word "train" in the title...  P.S.: If this is the wrong place  to ask, can someone refer me to the proper one? I've been meaning to find this out for a long time, but always put it aside.


method selectProduct() gets "java.lang.NullPointerException". error

I've stack with a selectItem() method. If I run it I get this error "java.lang.NullPointerException".  Definetly a problem with arrayList , but I  cant find out.  Any help, please.  Or an ArrayList better to create in a Dispenser class? If your need any more information I can give it. Thanks.      public class Dispenser     {        private String name; // Item name.        private int price; //Item cost.         private int stock; // Total quantity in stock.      /**     * Create a new dispenser with the given details.     * At the start it has 5 items in stock.     */     public Dispenser(String itemName, int itemPrice)     {         name = itemName;         price = itemPrice;         stock = 5;      }      /**     * Return an item name.     * @return Item name.     */      public String getName()     {         return name;     }   import java.util.*;      /**     * Main class for a vending mashine.      */      public class VendingMachine     {           private Dispenser disp;         private CoinBox box;        private int credit;        private ArrayList<Dispenser> items = new ArrayList<Dispenser>();           /**         * Constructor.         */         public VendingMachine()         {                 credit = 0;             items.add(new Dispenser("Snickers", 55));             items.add(new Dispenser("Mars", 50));             items.add(new Dispenser("Bounty", 75));       }         public void selectItem(String itemName)           {           for(Dispenser product : items){             if(disp.getName() == itemName){                System.out.println("Get Your " + itemName);          }      }          if((disp.getName() != itemName)){                System.out.println( itemName + " is Out of stock" );         }       }


MLE of $f(x\vert\theta)=1/\theta$, $x_1 , \cdots , x_n \sim U(0,\theta) \;\;, \theta>0$,

Original question  $x_1 , \cdots , x_n$ are independent random variables, identically distributed as  a uniform distribution over $(0,\theta)$.   $$ f(x \vert \theta) = \frac{1}{\theta}, \; 0<x<\theta, \;\; \theta >0 $$  What's the Maximum Likelihood Estimator for $\theta$.  Comment on strict inequalities  (from olooney, edited slightly)  The MLE does not exist if we use strict inequality. But  $x_i \sim U(0, \theta)$ has various definitions but makes the intent clear: to model the data as a uniform distribution. For a continuous p.d.f. any finite number of points has measure 0 and can be added or removed and the answer is "almost surely" (jargon for "with probability 1") the same.   Why not use a definition of the U which makes the MLE problem tractable and which is almost surely the same?  Note that the question has strict inequalities, not weak    Other similar posts to this  Though I searched others have highlighted other posts of a similar nature :


I would like to draw a vertical line in the plot, indicating the mode of the left gaussian.   \documentclass{article}  \usepackage{graphicx} \usepackage{pgfplots} \usepackage{tikz}  \pgfmathdeclarefunction{gauss}{3}{%   \pgfmathparse{1/(#3*sqrt(2*pi))*exp(-((#1-#2)^2)/(2*#3^2))}% }   \begin{document} \begin{tikzpicture} \begin{axis}[   no markers,    domain=0:90,    samples=300,   ymin=0,   axis lines*=left,    xlabel=$x$,   every axis y label/.style={at=(current axis.above origin),anchor=south},   every axis x label/.style={at=(current axis.right of origin),anchor=west},   height=5cm,    width=12cm,   ytick=\empty,   enlargelimits=false,    clip=false,    axis on top,   grid = major,   hide y axis,   xtick distance=10   ]  \addplot [very thick,cyan!50!black] {gauss(x, 45, 5)};  \addplot [very thick,red!50!black] {gauss(x, 55, 5)};   \draw[dashed] (45,-10) -- (45,10); \end{axis}  \end{tikzpicture}  \end{document}   However what I do get is the picture, but without the line. Why?


Separable differential equations: detaching dy/dx

I'm just learning about differential equation separability. I understand what a derivative is. One notation for derivative is $\frac{dy}{dx}$, which - misleadingly - is not a fraction. Since it's not a fraction, why are we "separating" differential equations by treating it as if it were a fraction? For example:  We have the following differential equation: $$\frac{dy}{dx} = y.$$  Then we separate the... whatever they are: $$\frac{dy}{y} = x\cdot dx.$$  What do $dy$ and $dx$ even represent when they are detached from each other? How is this valid math?  Then we integrate both sides of the equation. Even though we are integrating one side with $dy$ and the other side with $dx$, the equality is somehow magically not broken.  Also, somehow integrating $dy$ yields $y$, but integrating $dx$ doesn't yield $x$.  So my question is how do you make sense of $dy$ and $dx$ variables as they are separated from each other?


Dual boot (Windows 10 and Ubuntu 19.04) boots straight into Windows

I recently re-installed Windows 10 and Ubuntu 19.04 indual boot (curiously, the issue I am about to describe was not present before). When I boot my laptop it goes straight into windows rather than the menu where I can decide between Ubuntu, Windows  (the one with purple background). I tried to fix this with:   grub customizer in the UEFI settings with efibootmgr (running from an ubuntu live USB drive, ) with boot-repair (which produced )   Nothing solved the issue. Any ideas?  p.s: my laptop in a Dell Chromebook 13 (aka LULU) with full UEFI firmware by


Separating images from text in a scanned PDF document

Regular PDF files consist of vector elements, such as text and vector graphics, and other embedded data, such as image files. Extracting the latter is quite easy with utilities such as pdfimages (as described ).  On the other hand, scanned PDF documents are compilations of scanned pages. Every single page is a bitmap image, possibly overlayed with a searchable text layer produced by OCR. As a result, running pdfimages on a scanned PDF document will merely extract the scanned pages.  What I am looking for is an application or command-line utility that can distinguish between images and text in a scanned PDF document and extract the former.  Does anything like this exist?


This question is from an old Ph.D Qualifying Exam for Complex Analysis.    Let $\Omega\subset\mathbb{C}$ be an open set. Suppose that $f$ is holomorphic in $\Omega$. Define $g$ on $\Omega\times\Omega$ by $$g(z,w)=  \begin{cases} \dfrac{f(w)-f(z)}{w-z},  & w\neq z \\ f'(z), & w=z \end{cases}$$   Show that $g$ is continuous in $\Omega\times\Omega$.    My attempt: If $w\neq z$ then $g$ is clearly continuous, so we just have to consider the case of $w=z$. Clearly, for a fixed $a\in \Omega$, $\lim_{w\to a}(\lim_{z\to a}g(z,w))=f'(a)$, but the double limit need not be identical to the joint limit $\lim_{(z,w)\to (a,a)}$, so I'm not sure this is right. Does anyone have ideas?


Why I don't receive Exception if I use the object after I destroy it?

The following code works just fine, but it shouldn't ! When I click the Button1, the object is destroyed first, and then its Value is used and I don't receive any Access Violation or something... Even more, the multiply operation gives the correct result, that proves that Obj1 is not destroyed ! But then again, this is not true either, because when I close the program it does'n report any memory leakage. I'm very confused.  unit Unit1;  interface  uses   Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,   Dialogs, StdCtrls;  type   MyObj = class(TObject)    Value: Cardinal;   end;    TForm1 = class(TForm)     Button1: TButton;     procedure FormCreate(Sender: TObject);     procedure Button1Click(Sender: TObject);   public    Obj1:MyObj;   end;  var   Form1: TForm1;  implementation  {$R *.dfm}  procedure TForm1.Button1Click(Sender: TObject); begin  Obj1.Free;  Obj1.Value:=Obj1.Value * 5;  Caption:=IntToStr(Obj1.Value); end;  procedure TForm1.FormCreate(Sender: TObject); begin  ReportMemoryLeaksOnShutdown:=true;  Obj1:=MyObj.Create;  Obj1.Value:=10; end;  end.