How to find all questions that were duplicates of another question?

I am interested to see a list of all questions that were closed because being a dup of another question.  I strongly want to research a particular question and reading all the answers inside the dups will help me a lot.  Is there such feature? if not, this is a feature request


I have to calculate first 10 moments for vibrating string with damping, but I don't know how to do it. I read about moments and in definition they mention linear system $$x'=Ax+Bu, \qquad y=Cx$$ with  $$W(s)=C(sI-A)^{-1}B.$$ Then kth moment of a system above is $$C(sI-A)^{-(k+1)}B.$$ But for a vibrating string I know only wave equation $$Mx''+Cx'+Kx=b(t).$$ How to transform it to linear system?


Does bash recognize a variable declaration as string if you do not put the quotation marks?

name=Jackson echo $name   This will display Jackson.  name="Jackson" echo $name   This will also display Jackson.   So I assume by putting quotation marks around a variable it is making it a string. What would name=Jackson technically be? Would it also be recognized as a string?


"I have never seen him working", Is it grammatically correct?

He is very lazy. I have never seen  him working.   He is very lazy. I have never seen him work.      Are both of them grammatically correct? What is the difference in meaning between them?    Update:  I read the duplicate question, but I couldn't understand which one is correct in the above context. work or working?  I think work is correct, because it follows the verb tense in the first clause.  I think working is useful in another context. when the situation is temporary e.g.      It seem he is frustrating, I haven't seen him working recently.


Can I use these chargers interchangably?

I happen to own two android devices, a Huawei P30 Pro and a Samsung Galaxy Tab S5e. Both devices came with a charger, the specifications can be seen here   I'd like to charge both devices with one charger, is this safe to do and which one should I use? Does it make a difference?


one-time key, zero IV in stream cipher (e.g. AES-CTR)

Say I am using a random key to construct a stream cipher with, say, AES in CTR mode, which will never be used to encrypt more than one data stream. Is there any advantage, no matter how small, to using a random IV instead of an IV of zero? I repeat, the key will never be used twice.


Does one use 'a' or 'an' before the word X-Ray?

I was asking this question on Area 51: "How do I tell if an airport scanner is a X-ray scanner?", but I keep wanting to put an 'an' in front of X-ray because it starts with the 'eh' sound.  So is it 'a' or 'an'?


I am using Salesforce Lightning Design system and I'm currently working on a local html file and would like to create a button that when clicked, will cause a modal to open. I'd like to have a similar output like bootstrap modal that is triggered when a modal button is clicked. Is it possible to create a similar behavior without controllers? We will integrate it to salesforce later on.


I am trying to create my first basic model and render post tutorials. I have created a model of a Coke can (other soft drinks are available) and added a quick texture I aquired off google images.  The problem is that for some reason the texture does not appear to cover the entire face. I think the issue is related to the subdivision modifier I am using as if I turn it off then the texture appears correctly.   Issue   Subdivision turned off   I have done some googling but cant find anything, can anyone help?


I uninstalled wine thinking the Windows apps would go with it but they didn't and now they are stuck on my PC!

I uninstalled wine thinking the Windows apps I'd installed would uninstall with it but they didn't and now they're stuck on the PC.   I tried installing wine again but now they don't show in the add/remove program tab. I should mention that one of the games I installed, Far Cry 2 (which did not work at all) gave me an error when I tried to uninstall it. That was the reason for uninstalling wine in the first place, as I thought it would remove the game with it.  Any help would be appreciated. Thanks :)


While using TestNg framework my code throwing NullPointerException

I want to use TestNg in my learning project. While using TestNg framework, i am getting NullPointer Excetion. I think problem is in WebDriver object declaration part. But i don't know how i can implement the same. Can any one help me on the same?  Please find the code below,  package in.prolearn.testcases;  import java.util.concurrent.TimeUnit; import org.openqa.selenium.WebDriver; import org.testng.annotations.BeforeMethod; import org.testng.annotations.BeforeTest; import org.testng.annotations.Test;  import in.prolearn.pages.HomePage; import in.prolearn.pages.SearchResultPage; import in.prolearn.utility.BrowserSelection;  public class VerifySnapDealSelection {     WebDriver driver = null;      @BeforeTest     public void preCondition(){         driver = BrowserSelection.browserSelection("Chrome");         BrowserSelection.openBrowser("https://www.snapdeal.com/");     }      HomePage hp = new HomePage(driver);     SearchResultPage srp = new SearchResultPage(driver);      @Test     public void NavigateToSearchCategoryPage() throws InterruptedException{         hp.menuSelectionGeneric("Computers & Gaming");         Thread.sleep(5000);         hp.subMenuSelectionGeneric("External Hard Drives");         Thread.sleep(5000);     }     @Test     public void SearchResultPageValidation() throws InterruptedException{         srp.FirstcapacitySelection("1 TB");         Thread.sleep(5000);         driver.manage().timeouts().implicitlyWait(20, TimeUnit.SECONDS);         srp.FirstcapacitySelection("2 TB");         Thread.sleep(5000);         srp.verifySelectedItem("1 TB");         srp.verifySelectedItem("2 TB");         Thread.sleep(5000);         srp.DeleteSelectedItem("2 TB");         Thread.sleep(5000);         srp.VerifycapacitySelection("2 TB", "false");         srp.VerifyItem("1 TB", "1TB");         srp.DeleteSelectedItem("1 TB");         Thread.sleep(5000);         srp.VerifycapacitySelection("1 TB", "false");     } }


Disallow downvoting other answers if I've posted my own

Possible Duplicates:        As Dan Dyer mentioned in his comment on , there is a conflict of interest when you have posted your own answer and are allowed to downvote other answers.  Despite the vote editing window being drastically reduced, the fundamental problem remains: I can downvote the other answers permanently and still benefit - my answer gets upvoted ONCE and wham, I have just made up the rep loss for my 10 other downvotes. The vote editing window fixes part of the problem, but there is a more complete fix that has the extra benefit of not preventing legitimate vote changes: to disallow downvotes on competing answers when you have posted one yourself.  The temptation to wrongfully downvote competing answers is huge. The rep loss is tiny in comparison. It has to be in order for people to continue to legitimately downvote.  Details:   If I have previously voted and then post my own answers, delete my downvotes. Continue to allow me to remove the upvotes - I think this is fully legitimate. If I delete my answer it's probably best to continue to deny downvotes (perhaps even including the question), but I don't have a strong opinion either way.


Trying to rotate a line upon a button click in Netbeans

I am trying to use Netbeans GUI Builder to rotate a line upon a key press. The code is simplified but I will answer any questions.  I have gotten the actual rotation to work separately but putting it together with the buttonpressed gives me the following error:  Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException     at exam2.Exam2.jButton3MouseClicked(Exam2.java:372)     at exam2.Exam2.access$200(Exam2.java:18)     at exam2.Exam2$3.mouseClicked(Exam2.java:222)     at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:270   myMouseClicked event which reads whatever the new value in the jtextfield is and saves it in newhour.  //function of JFrame   private void jButton3MouseClicked(java.awt.event.MouseEvent evt) {                                           setHour();     Integer newHour = (Integer) currentHour +1;     String newHourStr = newHour.toString();     jTextField1.setText(newHourStr);     myCanvas.updateHour(newHour);  //this is where the error occurs }    //function of Canvas which extends JPanel public void updateHour (int currentHour) {     currentHour = getHour();     System.out.println("the hour at hand" + currentHour); //does not print this     int currentAngle = currentHour*30;     Stroke stroke = new BasicStroke(3f);     g2d.setStroke(stroke);      double lengthHour = Math.pow(Math.pow(centerX-this.getWidth()/2,2)+Math.pow(centerY-(this.getHeight()/2)-radius,2),0.5);      int xHourChange = (int) (lengthHour * Math.cos(Math.toRadians(currentAngle)));     int yHourChange = (int) (lengthHour * Math.sin(Math.toRadians(currentAngle)));     g2d.drawLine(centerX, centerY, centerX + xHourChange, centerY - yHourChange); }   //function of Canvas which extends JPanel public void paintComponent(Graphics g){     g.setColor(Color.WHITE);     g.fillRect(0, 0, this.getWidth(), this.getHeight());     g.setColor(Color.BLACK);     drawCircle(g);     drawFace(g);     drawHour(g);  //this works perfectly     //drawMinute(g);     //drawSecond(g); }


Convergence of series depending on convergent series

I have a convergent series of positive terms $\sum_{n=1}^{\infty} a_n$ and have to check if series $$ \sum_{n=1}^{\infty}\frac{\sqrt{a_n}}{\log(n)}\left(n^{a_n}-1\right)$$ converges. I think it does, but don't know how to prove that, I tried using Cauchy criterion, but couldn't really make it work.


Blender isnt letting me import any SVG files

I'm very new to blender but I've recently watched hundreds of tutorials showing me how to import svg files.  It seems very easy, a simple 1, 2 step posseces but for some odd reason I'm having no luck getting it to work.  At first I thought maybe I'm not saving my file correctly so I when on google and seached SVG files formatted down to the t.  I still have NO LUCK at all even gettin one out of the 20 professional svg files to work.  I'm starting to think maybe blender file might be corrupted.  Is there anyone eles who has had this problem where they were unable to get a single SVG file to import into the program.  I would love to hear how I can resolve this issue so that I can enjoy making countless of projects I have in mind


"That solved my problem" doesn't make sense if the target question is unanswered

Can we get an alternative to the "That solved my problem!" button that doesn't make the presumption that it solved my problem? I.e. "Yes, that's the problem I have."  In some cases, SE (et. al.) answer something, but the answer really doesn't solve it, it was a "cop-out" -- a "we know there's a problem, but there's currently no fix or workaround". Can we get a button that indicates that "Yes, I acknowledge I have that same problem, and I may have even tried those solutions, but it's not solved by any means." button or something?  I get the purpose of it - make it more friendly and easier to remove duplicates, but I refuse to say "That solved my problem!" if I still have a problem (mostly on principle). I'd rather have a "Ah yes, that's my issue! But, it seems like there's no actual solution there."  As an example:


Variance inflation factor vs condition number

We know the Variance inflation factor and condition number both help to measure multicollinearity. Which one should we use when?


Who was flying the Y-Wing when the Death Star exploded?

Near the end of Star Wars IV: A New Hope, we see four spacecraft flying from the Death Star just moments before it explodes.     As you can see, there is the Millennium Falcon crewed by Han and Chewbacca, a pair of X-Wings which has to be Luke and Wedge, and then in the bottom corner, we see a Y-Wing. Who is this pilot and did he have any screen time to justify him actually existing in this moment? For as far as I can tell during the first trench runs, they were conducted by the Y-Wings and all of them seemed to have been destroyed during their run. So as I asked, who is flying this ship and how did survive to this moment?


Question about interpreting probabilities in QM

For the example of an infinite square well, $\psi(x)=0$ for $x$ outside the well/interval, and we are to interpret this as the particle cannot be found outside the well because $|\Psi(x,t)\bar{\Psi}(x,t)|^2=0$ in these regions. But probability of $0$ does not necessarily imply that an event is impossible, so I'm a bit confused as to why you can say that it's impossible for the particle to be in this region or that just based off of this. Can anyone clarify?


Java IF statement not outputting correctly

I'm new to this site :)  Anyway, I decided to learn java a couple of days ago and I have a small problem which I don't know how to fix. This is my code: When name = Jim I want it to output "Hello Jim", when it doesnt  = Jim then output "Youre not Jim, youre " + name  import java.util.*; public class app {     public static void main(String[] args) {         String name;         Scanner inputName = new Scanner(System.in);          System.out.println("Enter a name: ");         name = inputName.nextLine();          if (name == "Jim") {             System.out.println("Hello " + name);         } else {             System.out.println("Youre not Jim! You are " + name);         }      } }


“This computer currently has no detected operating systems.”

I have got my new PC with Windows 10 installed on it. I am now trying to install Ubuntu which is the main OS I need, However since I have paid for Windows license, I do not want lose it! Will this happen if I Erase the disk and install Ubuntu? If yes, how much space is enough to give to the Windows partition in order to just keep it.  Will I be able to change the partition size later after installation?  While I'm installing Ubuntu it says:      This computer currently has no detected operating systems.   Why doesn't it detect the Windows? :(


How to convert an existing Windows machine to VirtualBox?

I have VirtualBox installed on my Linux machine (Debian). I need to move a physical Windows 7 machine into my VirtualBox.  How to convert a physical Windows OS to VirtualBox?


What should be the mesh count when I submit a model?

I have been planning to upload a 3D model lately. What is the actual definition of  polygon numbers as I don't know what subdivision level is taken as the standard for my submission. The 3D website didn't state which subdivision level of my model should be taken as the standard for polygon counting. Any help is appreciated.


I have trouble to comprehend what my mistake is in the following calculation:  If we set $\sqrt{-1}$ to be the new number with the property that $(\sqrt{-1})^2 = -1$ then I can write $$\frac{1}{\sqrt{-1}}=\sqrt{\frac{1}{-1}}=\sqrt{-1}.$$  But we also have (and I know this is the correct result) $$ \frac{1}{\sqrt{-1}}\cdot\frac{\sqrt{-1}}{\sqrt{-1}}=\frac{\sqrt{-1}}{-1}=-\sqrt{-1}$$  What am I missing? Thanks.


Does the following inequality hold? If matrix $A$ is a $n \times n $ positive semi-definite, $A \succeq 0$, and $U$ is one $n \times k$ unit column-orthogonal matrix ($k \leq n$), $U^{T}U=I$, do we have  $$A \succeq UU^{T} A U U^{T}$$ ?


Throwing a ball from the surface of the earth so that it ends up in a circular orbit

Assume the Earth to be a uniform sphere of mass M and radius R. Also let the Earth be stationary initially. Assume further that there is all other stellar bodies are very far away so as to have no influence in this problem.  A ball of mass $m$ is to be thrown from the surface of the Earth so that it ultimately ends up moving in a circular orbit at a height $h$ from the surface of the Earth. How should the ball be thrown, as in, what should be its initial velocity and, in particular, what should be the angle $\theta$ of the initial velocity with the radial vector from the Earth's center to its initial position on the surface of the Earth?  My attempt at the solution:  Since the Earth-ball system is isolated, its energy would be conserved. Let the initial speed of the ball be $v_0$ and the final speed be $v_f$. We'll have the following equation:  $$ \frac{1}{2}m v_0 ^2 - \frac{GMm}{R} = \frac{1}{2}mv_f^2 - \frac{GMm}{R+h}$$   Next, we know that when the ball will finally be in circular orbit, the gravitational force will be providing the necessary centripetal acceleration for it to maintain circular motion, which gives us the following equation:  $$ \frac{mv_f^2}{R+h} = \frac{GMm}{(R+h)^2} $$  Besides, since gravity is a central force, the angular momentum of the ball about the center of the Earth will remain conserved, which yields the following equation:  $$ mv_0R \sin(\theta) = mv_f(R+h) $$  That completes setting up three equations for three variables $- v_0, v_f, \theta $. Solving them, we would obtain the following values for each:  $$ v_o = \sqrt\frac{GM(R+2h)}{R(R+h)} $$   $$ v_f = \sqrt\frac{GM}{R+h} $$  $$ \theta = \sin^{-1} \Biggl( \frac{1+\frac{h}{R}}{\sqrt{1+\frac{2h}{R}}} \Biggr) $$  However, it is observed that for $\theta$, the argument of $\sin^{-1}$ is always greater than or equal to one, being one only if $h$ is zero. The proof may be carried out by initially assuming that the argument of $\sin^{-1}$ is less than or equal to one for $h$ greater than or equal to $0$, and solving the inequality will yield that $h$ must be less than or equal to zero. So the only acceptable solution is for $h$ to be zero. This just winds up being the case of throwing the ball with sufficient speed tangentially on the surface of Earth so that it keeps orbiting on the Earth's surface itself. Thus, there is no possible way to just throw a ball so that it ends up in a circular orbit of certain desired radius.  The problem is that I don't see any physical intuition for why this should be true; either that or I am doing something wrong. Any guidance or help would be greatly appreciated!


AES-CBC ciphertext manipulation with known IV and plaintext!

I'm currently practicing on a purposely flawed login page, where I have to change the value of a cookie to enter. The cookie is an encrypted and encoded form of a simple JSON string with fields "admin", "username", "password". The admin field is set to 0, and the user/pass fields accepts anything. To login, I have to change this ciphertext such that the admin field is set to 1 when decrypted.  The encryption function works like this:   A raw string is padded, then encrypted with AES-CBC and a random IV. Then, this cipher text appends the IV (concatenation; IV+cipher).  Then, this is Base64 encoded, and returned.   So, to decrypt, we simply decode it with Base64, and split the result so that the 16 first characters are the IV, and the remaining is the ciphertext.   Now, I want to know the ciphertext when one character of the plaintext is changed.   Specifically, in my example:  The following string is encrypted, appended to the IV, and encoded:  {"admin": 0, "username": "admin", "password": "admin"}  This apparently results in the encoded text (found in cookie):  yMqlNejXMclgcU5+wbL40RY/mvIMW+AvguoMvCv0NemhRYzWzs7EQ2DXpvwsGmFynGpNWNyotYBea+P3Z3XZIvMBoMzdMVb/FtWQ+GV/MmA=  I'd like to know what this encoded text / cookie looks like if the plaintext is changed to {"admin": 1, "username": "admin", "password": "admin"} (note, the 0 changed to 1). The username and password can be anything, only the "admin": 1 part is important.  It appears the key is fixed, but the IV is generated at random every time I try to logout and login again.  Is this possible? If so, how?  Thanks!


Is it allowed in DNS to have a CNAME record that points to another CNAME record?  The reason we need this is that we have a hostname that we want to be looked up to the IP address of our web server computer. We also have another web server computer stand by that could be activated in case the first one would die. In such a case we would quickly need to point the hostname to the IP address of the stand by web server computer.  Unfortunately the hostname resides in a DNS domain where any change would take long time due to manual operation dependent on other sysadmins. But we have another DNS domain where we can perform the changes ourselves quickly. Having CNAME to CNAME chain seems like a possible solution. But is it allowed? Will web browsers understand it?


How to merge two sorted list in python in linear time(traverse only once)?

list_a = [1,7,9,35,36,37] list_b = [3,4,5,40]   Expected output:  list_merged = [1,3,4,5,7,9,35,36,37,40]   Condition : must traverse both list only once  I know of zip which works as below and does quite fit in my requirement.  >>> x = [1, 2] >>> y = [1, 3, 4, 5, 6] >>> zip(x,y) [(1, 1), (2, 3)] >>> zip(y, x) [(1, 1), (3, 2)]


Using CURRENT map document in Python script tool?

I am attempting to use this code in a tool that I am working on:  mxd = arcpy.mapping.MapDocument("CURRENT") df = arcpy.mapping.ListDataFrames(mxd)[0] XMIN = df.extent.XMin YMIN = df.extent.YMin XMAX = df.extent.XMax YMAX = df.extent.YMax   I then go on to do other calculations with the extent. The code works perfectly in the Python window, but because Toolbox tools are run in separate processes I am unable to use "CURRENT".  I think I could probably add a derived input variable and pass the coordinates through the validation script, but that doesn't work for what I am doing. I need to be able to do this later on in the script and add an additional temporary feature to the current map:  points = arcpy.CreateFeatureclass_management("in_memory", "NewFeature", "POINT") arcpy.AddField_management(points, "NewField", "TEXT", "", "", 20)   I know all of my code works right, because I can paste the entire .py into the  Python window and then call Main() and run through it, but I need to share it with others in an easier way.   I would prefer the solution be compatible with 10.0 and 10.1 if at all possible, because some of the people I work with do not have 10.1 yet. I will accept a 10.1 only solution if I have to though.  What options do I have to do this?    I still can not get this to work, they have not gotten me Python Add-In Wizard yet so I am unable to test that approach. I have again tried the "Run in process" box checked and unchecked. Neither are working.   Checked gives me this: RuntimeError: CreateObject cannot open map document  Handled that exception: Object: CreateObject cannot open map document  From my testing looks like it is having the same error running in process or not.    I will still be attempting to do this within the Add-In Wizard, when they finally give me it.  The winning answer is I wasn't running it in the foreground.


I'm travel from Kenya to Amsterdam to Athens is that need a transit visa? Or any kind of visa I'm a permanent resident of Greece

I want to travel from Kenya to Amsterdam and to Athens. Does that need a transit or any other kind of visa? I'm a permanent resident of Greece and I travel with my Kenyan passport.


Compute Lebesgue measure of set of all real numbers in $[0,1]$ whose decimal representations don't contain the number 7

Consider measure space $(S, \Sigma, \mu) = (\mathbb R, \mathscr B(\mathbb R), \lambda)$.  Let $V^C \subseteq S$ denote the set of all numbers in $[0,1]$ whose decimal representations don't contain the number 7.   Prove that $V^C \in \Sigma$. Compute $\lambda(V^C)$.     What I tried:   I think we have   $$V = \bigcup_{n=1}^{\infty} V_n$$  where $v_n \in V_n$ can be written $v_n = 0.s_1s_2...$ where $s_1 \ne 7, ..., s_{n-1} \ne 7, s_n = 7$  $$V_n = \bigcup_{s_1, ..., s_{n-1} \ne 7} [0.s_1...s_{n-1}7, 0.s_1...s_{n-1}8)$$  $V$ is a finite union of pairwise disjoint $9^{n-1}$ intervals and hence is a Borel set, which is Lebesgue measurable.  $V$ is a countable union of  pairwise disjoint Borel sets and hence is a Borel set, which is Lebesgue measurable.  Thus, $V^C$ is Lebesgue measurable.  2.  $$\lambda(V) = \lambda(\bigcup_{n=1}^{\infty} V_n) = \sum_{n=1}^{\infty} \lambda(V_n)$$  $$\lambda(V_n) = \lambda \left(\bigcup_{s_1, ..., s_{n-1} \ne 7} [0.s_1...s_{n-1}7, 0.s_1...s_{n-1}8)\right)$$  $$= \sum_{i=1}^{9^{n-1}} \lambda ([0.s_1...s_{n-1}7, 0.s_1...s_{n-1}8))$$  $$= \sum_{i=1}^{9^{n-1}} \frac{1}{10^n} = \frac{1}{10^n} \sum_{i=1}^{9^{n-1}} (1) = \frac{1}{10^n} (9^{n-1} - 1 + 1) = \frac{9^{n-1}}{10^n}$$  $$\to \lambda(V) = \sum_{n=1}^{\infty} \lambda(V_n) = \sum_{n=1}^{\infty} \frac{9^{n-1}}{10^n} = 1$$  $$\therefore, \lambda(V^C) = 0$$


I want to list the partitions on my phone - system, boot, recovery etc. What terminal command should I use? The mount command just lists mount points.


I know that $ a\cdot\left(\frac1a\right)=1$  as long as $a$ is not $= 0$,  but when we divide $(\frac a0)$ is $=$ we say it's undefined.   why is it really undefined? what's the big conspiracy here.


How to set global variable in functions.php

I want to be able to echo the URL of the featured image of a post and after looking some on the web I found the following which works fine when I put it in a loop in my front page template.   <?php $thumbSmall = wp_get_attachment_image_src( get_post_thumbnail_id($post->ID), 'small' ); $urlSmall = $thumbSmall['0']; ?>  <?php echo $urlSmall; ?>   However, want to use variable $urlSmall in other places than in the front page template, and this is where my limited coding skills let me down. I tried to just copy paste  wp_get_attachment_image_src( get_post_thumbnail_id($post->ID), 'small' ); $urlSmall = $thumbSmall['0'];   into my functions.php but that did not work. I need these variables to be globally recognized. What do I do here? write some kind of function?


Could we have the ability to mark a change as minor in questions or answers?

It would be nice to allow users to mark a change in an answer (or question) as minor (e.g. for a simple spelling or grammar correction). A change marked as minor wouldn't push the question on top of the list of questions on the home page or in the feeds. It wouldn't trigger any notification. This could be implemented with a "Minor change" checkbox when editing an entry (a la Confluence). What do you think?


Difference between `sudo su` and `sudo fish`

I am running fish (Friendly Interactive Shell) as my standard shell in Ubuntu 14.04, rather than bash.  I noticed the following behaviour and don't know, if any of these are the preferred one to gain root access.  I can type the command sudo su or sudo fish and it will both give me super user rights. (The prompt is displayed as root@ubuntu ~#) Is there any difference in the behaviour of these commands?  The only thing I could understand is, that sudo su uses the fish configuration located in /root/.config/fish/ and sudo fish uses the fish configuration in my home directory /home/uloco/.config/fish.  Is there a possibility to crypt my system by using sudo fish? Will there be any owner changes made to files in my home directory if I use this?


No more disk space: How can I find what is taking up the space?

I've run into a problem on one of my servers running 16.04: there is no disk space left.  I have no idea what is taking up the space. Is there a command to list the current directory sizes, so I can traverse and end up in the directory taking up all the space?


I'm unsure what the current procedure for package security for Ubuntu is.  When something ends up in the Ubuntu package repositories, are the package audited by a central, trusted team and if so what level of auditing takes place?  I'm interested on whether packages are checked for:   Regular matching against known vulnerabilities/CVEs (as in, package maintainers are notified in realtime of CVE releases, and packages with unpatched (by vendors) CVEs removed). Obvious malicious code (eg reverse shells, random shell code, trojans) Poor code quality (eg unintended command injection vulnerabilities) Full security audit of all code for vulnerabilities


How to calculate the volume of the $4$-dimensional closed sphere?

I started by integration of 3D formula for sphere volume. Not good or? The closed sphere has a centre $(0,0,0,0)$ and a radius $a > 0$ in the $4$-dimensional space: $x^2 + y^2 + z^2 + w^2 \le a^2$.


I need a .htaccess expression to use the second get variable or get the get variable by name. Currently my mod_rewrite alters the URL to remove index.php filename and alter the pageName GET variable so that it just looks like a filename.   I now need a second GET variable, but currently the way it is, it does not even recognise get variables after the first rewrite, so I would like the mod_rewrite to handle the second var which will be 'blogpage=1'(1 will be the blogpage that you are currently on) so that it will look like so:  *********.co.uk/PageName/2   instead of this  *********.co.uk/PageName?blogpage=2   As this does not currently work, the PHP script simply thinks that the var is not present and returns a NULL value.  This is my current mod_rewrite conditions:  RewriteCond %{REQUEST_fileNAME} !-d RewriteCond %{REQUEST_fileNAME} !-f RewriteRule ^([^/\.]+)/?$ index.php?pageName=$1


How do I create a D&D character correctly as a total newbie?

I am a brand new player trying to create a character for D&D 5e. I have the PHB and a character sheet and am trying to figure out how to proceed, and I'm getting stuck a lot.   I have the normal character sheet for 5e from the D&D website, but lots of the boxes make no sense to me. The character creation seems to require a lot of back and forth throughout the entire book and it's very confusing. I was able to figure out my class (rogue), and race (high elf). I found out my proficiency bonus, and did my stats, but other than that I really don't know what I'm doing. I have lots of small questions that I can't really type into google, and the index in the book has been a life saver but only goes so far. But I am left with a large number of questions I'm having trouble finding the answers to by looking them up in the index, like:   What number and above is a success for a death save? What number and below is a fail? What are the lines next to the skills for? What do I put in personality traits? Is that just for fleshing out your character, or is it important to how you play the game? What do I put in bonds? Is that important or just fleshing out? What do I put in flaws? Important or fleshing out? What do I put in ideals? Important or fleshing out? What do I put in "other proficiencies and languages" What do I put in equipment and character notes? What do I put in features and traits? How do I fill out my attacks and spell casting sheet? And more.   How do I get started to where I understand the rules enough to fill out a character sheet like this?  There's a lot to the game, it appears, and I have some familiarity with the lingo from Geek and Sundry's Critical Role, but the learning curve seems really high.   D&D looks like a TON of fun, but I need a character first, ya know? How can I get through all these details so that I can get started?


Can we have an RSS feed for the /review page?

This came up in the mod chat earlier today. Would it be possible to add RSS feed support for the /review page?    This makes zero sense now that /review has been completely redone, and the jury's out on whether or not this ever made sense. So I get to status-decline my own request. :)


Do I need to use McLaurin to solve the integral $ \int \frac{e^{3 x}}{x^3} dx$.

I need to compute this primitive :     $$ \int \frac{e^{3 x}}{x^3} dx$$   but I don't know how to proceed. I tried an integration by part and get     $$ \int \frac{e^{3x}}{x} dx$$   but then I am stuck... Is there no way else than making a McLaurin development ?  Thanks


What are the key differences between 2.4 Ghz and 5 Ghz Wifi distribution?

On my replaced Wifi router, I noticed that there is a choice to make regarding the frequency distribution.   802.11g network that run at 2.4 GHz. 802.11a network that runs at 5.0 GHz.   Does the Quality of Service get affected by selecting different frequencies? I read both supports up to 54 Mb/s, so max bandwidth might be irrelevant. So why would you run a 5 Ghz network frequency?   Also, I noted that some cordless phones runs at 2.4 Ghz, defining one of Cisco's rules - keep away the Wifi router from devices like those. Most Wifi routers do run at 2.4 Ghz, but if there  is interference, and you are too lazy to move the router, would you really go and spend the money on a 5 Ghz - supported router?


How to get lower resolution image in current clipboard after using macOS screen-capture shortcut?

I have set Command + Shift + 4 to a keyboard shortcut to take a screenshot and save to clipboard, usually, I will paste this image for next usage.  But I want to lower the resolution of the image in the current clipboard because it's too big, how to do this?


How to reference sections in other parts mentioning the part?

I have an article class document with a structure like this.  Part A  Section 1 Section 2   Part B  Section 1 Section 2    I want to reference Section 1 in part A from Section 2 in part B. When I reference a section in another part using \ref, \vref or \cref I get  As seen in Section 1.  Since that appears in Part B, the reader would assume I'm talking about section 1 in part B, but I mean section 1 in part A. Desired output:  As seen in Section 1 in Part A.  Now comes the tricky part. Most of my references are for within the same section. If I'm in Part B and I'm referencing something in Part B, I just want to say  As seen in Section 1  Not  As seen in Section 1 in Part B  Is there some combination of varioref,hyperref, cleveref and whatever else which can do that with a single command? (Bonus points if it is hyperlinked and can include smart page numbers like \vref) I suppose redefining section numbers to be of the form A.1 would work. Is there a way of doing it without that? MWE \documentclass[a4paper]{article}  \usepackage[english]{babel} %do I need this? Gummi throws an error if I leave it out. I dunno. \usepackage{varioref} \usepackage[hidelinks]{hyperref} \usepackage[nameinlink, capitalise, noabbrev]{cleveref}   \begin{document}  \part{First Part}\label{sec:first part}  \section{section in first part}\label{sec:in first part}  \part{Second Part}\label{sec:second part}  \section{section in second part}\label{sec:in second part}  \Cref{sec:in first part} is cool %desired output: Section 1 in Part A is cool.   \Cref{sec:in second part} is also cool. %desired output: Section 1 is also cool.  \end{document}  Edit: The penultimate line is supposed to say 'this part' not 'another part'. Disambiguated the reference sentences.


What points in the complex plane satisfy $|z|=arg(z)$.

Question: What points in the complex plane satisfies $|z|=arg(z)$.  Work thus far: Let $z=a+bi$ and $arg(z)$ is the angle between the vector $z$ and the axis. So $|z|=\sqrt{a^2+b^2}$ and $a=|z|\cos(\theta),b=|z|\sin(\theta)$. I would expect from intuition that the shape traced out by the points is a spiral. From here I don't how to proceed. Any hints would be appreciated.


On some user profiles, e.g.  image proportions are broken:        Image on activity tab or on  page isn’t distorted:        The issue is probably related to the old one:


Currently moderators have the ability to lock posts, for any of the following reasons:   Content dispute (~ edit wars), Historical significance (to prevent great but off topic questions from being deleted), and Offtopic comments Wiki Answer   The locks can be applied for an hour, a day, a week, or permanently. This is all great, but:   Locking a post also prevents voting and (more importantly) editing, and  If the locked post is a question, there are other ramifications, such as preventing new answers from being posted.   Those side-effects aren't always desirable for posts that generated a lot of "offtopic comments" and I think we could use a lock that would only lock the comment section. The lock message should point to chat, and ideally should also give the option of migrating the comment thread to chat automagically.  Additionally the comment lock, being a lesser lock, could be available to the OP as well, not only to moderators. Perhaps only after a certain rep level (3K? 5K? 10K?) and perhaps without the option to lock permanently. Getting spammed with inbox notifications on an irrelevant discussion happening on one of your posts isn't fun, and it's perhaps the only thing I truly hate on Stack Exchange.  Similar feature requests:    (duplicate?)    Relevant discussions:


1.Have you phoned your sister?      2.Did you phone your sister?   What is the difference between the above two sentences? (Do they sound similar?)


System settings not launching on Ubuntu 18.04

From the drop-down menu, top right corner, I have access only to the volume, brightness control, and power on or off buttons.   None of the other icons launch, including Account Settings, Wifi control, wired connection, and the control center.   Output of apt policy gnome-control-center:  Installed: (none) Candidate: 1:3.28.2-0ubuntu0.18.04.2 Version table:    1:3.28.2-0ubuntu0.18.04.2 500       500 ca.archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages    1:3.28.1-0ubuntu1 500       500 ca.archive.ubuntu.com/ubuntu bionic/main amd64 Packages


I'm using todonotes to make notes on my thesis. I'd like to be able to put some dot-points on a couple of the larger notes, like this:  \todo[inline]{   \begin{itemize}     \item blah blah blah   \end{itemize} }   But I get this error message:  ! Argument of \reserved@a has an extra }. <inserted text>             \par l.9 }   Is there anything I can do to get around this, or is it basically not worth trying?


Why can visible light go through green-house gases?

I understand that visible light can (largely) go through greenhouse gases, but infrared radiation can get reflected back... why can visible light go through green-house gases?   Does it have to do with shorter wave-length of the visible light? i.e. are green house gases like a sieve that only allow shorter wavelengths in?


New lock type: "Official Announcement Lock"

I have wanted to propose something along these lines, but a comment by rjzii  it very well:     @GeorgeStocker In all fairness, an official SE post should just be locked from the beginning as a matter of policy. I'm not sure if the back-end supports locking the question and still allowing responses to be made.   During the time that the announcement in question was locked, it was not possible to add answers to the question, comment on it, or vote on it, even though the purpose of the lock was apparently just to protect the exact content/text of the question (as it was an official announcement and not a problem statement with scope for community improvement), rather than to prevent answers, voting, etc.  Let's create a new lock, the Official Announcement Lock (TM). This lock will prevent edits to the question, and possibly closure, but will allow all other actions - commenting, answering, adding bounties, and voting up or down. The text might look like this:     Locked as an official announcement. This is an official announcement from Stack Exchange and may not be edited by the community. If you wish to provide constructive feedback on or respond to this post, you may vote on it or post an answer. If you believe that this post needs an edit, flag the question or raise a new question on Meta.


Flash plugin in Chromium available in 16.04?

Now that I've installed 16.04, I'm not able to view news that require Flash for streaming on Chromium. I've installed Flash, and the plugin works on Firefox. Is there a different plugin I should try for Chromium?


How do you factorise $x^3z - x^3y - y^3z + yz^3 + xy^3 - xz^3$?

I'm trying to factorise $$ x^3z - x^3y - y^3z + yz^3 + xy^3 - xz^3 $$ into four linear factors.  By plugging it into WolframAlpha I've learned that it's $$-(x-y)(x-z)(y-z)(x+y+z)$$  My question is: what are the steps involved in factorising the expression? Is there a method I don't know about that I'd have access to with my limited maths?  Really appreciate any help!


Removing Ubuntu 15.1 and installing Windows 7 Ultimate

I know just enough to get myself in trouble when it comes to computer stuffs.  I am trying to remove Ubuntu from my laptop (an Acer Aspire) and install Windows. If I put in the boot disk and select the disk as my boot device, I can access start up, but run into a problem. Something about how it can't install Windows onto the partition. (Two are available, the primary partition and one that has 1 MB of space. I don't know why.)  So I tried another method-formatting the hard drive. This also failed, as when I tried, I got the error:  Error unmounting /dev/sda1: Command-line `umount  "/dev/sda1"' exited with non-zero exit status 32: umount: /: target is busy         (In some cases useful info about processes that          use the device is found by lsof(8) or fuser(1).)  (udisks-error-quark, 14)   I have no idea where to go from here. I'm totally and utterly lost. Help?  I've reviewed other similar questions, and none explain how to deal with the problem I face here.


Link Google Form responses To Already Existing Google Spreadsheet Tab

I have a Google Form. I had all of my Google Form responses linked to a specific tab in my Google Spreadsheet. Somehow my form responses were unlinked from my tab. When I go to re-link my form responses to my already existing tab it only gives me the option to create a new tab in my spreadsheet.   How do I simply re-link my Google Form responses to my already existing tab in my Google Spreadsheet?


what is the simplified expression for the sum of probability of exponential distributed data?

Hi, I want to find the expression of P(Y1+...+Yn>U) as shown in the screeshot below but I have no idea how to do this. I'm not sure whether I should use Erlang distribution or gamma distribution. Please advise. Any help will be greatly appreciated!


How to copy/paste parts of a text in Messages.app

I am pretty sure I used to be able to select and copy text in Messages.app like in any other app (click + drag, double-click, etc.)  Right now I don't seem to be able to do this.  I am not sure what updated last, I am on macOS 10.14.6, Messages.app 12.0  Use case:    How do I copy the code from the message?


Python code works with print but not return

In the following code, I need to return b so that I can use it in another function. I tried testing to see if b would be returned but when I run def main and print(n_boxes), it gives me None. However if I changed return b to print(b) and print(n_boxes) to n-boxes, I get the correct output.     def subsets(a, b, lo):     hi = len(a)     subs_2 = []     if (lo == hi):       return b     else:       c = b[:]       b.append(a[lo])       subsets (a, c, lo + 1)       subsets (a, b, lo + 1)   def main():     boxes = [[1, 2, 3], [4, 5,6], [6, 6, 9], [3, 8, 4]]     b = []     n_boxes = subsets(boxes, b, 0)     print(n_boxes)   main()   I am not sure what I am doing wrong. I need the values for b. Thanks!  Ok so I want all possible subsets to be returned. The "def subsets" can do that. With "print b" my output is  [] [[3, 8, 4]] [[6, 6, 9]] [[6, 6, 9], [3, 8, 4]] [[4, 5, 6]] [[4, 5, 6], [3, 8, 4]] [[4, 5, 6], [6, 6, 9]] [[4, 5, 6], [6, 6, 9], [3, 8, 4]] [[1, 2, 3]] [[1, 2, 3], [3, 8, 4]] [[1, 2, 3], [6, 6, 9]] [[1, 2, 3], [6, 6, 9], [3, 8, 4]] [[1, 2, 3], [4, 5, 6]] [[1, 2, 3], [4, 5, 6], [3, 8, 4]] [[1, 2, 3], [4, 5, 6], [6, 6, 9]] [[1, 2, 3], [4, 5, 6], [6, 6, 9], [3, 8, 4]]   I want to be able to use the above subsets individually. So I am trying to find a way to return the subsets and be able to write a function that will give me subsets of length two. To clarify, I would be able to write such a function, but I would need the individual subsets first.


I know, questions like this have been asked before, but I'd like to get some up to date experiences.. From what I've read in various discussions, BTRFS seems like it's relatively stable, but once in a lifetime, with some kind of an upgrade it breaks (don't know how old this info is...). I'm sure, many of you are using BTRFS right now and I'd like to switch to it too, I'd just like to know if YOU consider it stable, had any problems with it, and, well, would you trust it to handle your.... let's say semester project?


Proving the Jacobi method converges for diagonally-column dominant matrices

The Jacobi method is an iterative method for approaching the solution of the linear system $Ax=b$, with $A\in\mathbb{C}^{n\times n}$, where we write $A=K-L$, with $K=\mathrm{diag}(a_{11},\ldots,a_{nn})$, and where we use the fixed point iteration $$\alpha_{j+1}=K^{-1}L\alpha_j+K^{-1}b,$$ so that we have for a $j\in\mathbb{N}$: $$\alpha-\alpha_{j+1}=K^{-1}L(\alpha-\alpha_{j}).$$  Now my syllabus provides a proof for convergence for the case that $A$ is diagonally-row dominant, but I and our teacher both couldn't see a way to rewrite the proof to a proof for the diagonally-column dominant case. The proof for the diagonally-row dominant is given using the $\|\cdot\|_{\infty}$ norm, and I found on the internet that the diagonally-column dominant case can be proved using the $\|\cdot\|_{1}$ norm. The proof strategy would be to show that $$\|\alpha-\alpha_{j+1}\|\leq \rho^j\|\alpha-\alpha_1\|,$$ for some matrix norm $\|\cdot\|$ and a $0\leq\rho<1$, from which convergence would follow immediately.   Does anyone have an idea how to continue? Using the $\|\cdot\|_{1}$ norm as suggested by the internet we want to have something like $$\|\alpha-\alpha_{j+1}\|_1\leq\|(K^{-1}L)^j\|_1\cdot\|\alpha-\alpha_1\|_1,$$ and somehow conclude $\|K^{-1}L\|_1$ should be bounded by $1$. I know about the characterization $$r:=\max_{i\in\{1,\ldots,n\}}\Bigg\{|a_{ii}|^{-1}\sum_{\substack{i&=1\\ i&\neq j}}|a_{ji}|\Bigg\}.$$  I'd like to proof this without Gershgorin's theorem, since this is not covered in my course. It is fine if the case follows from the diagonally-row dominant case.


I am trying to clarify my understanding of terminal here.  Terminal is actually a device (keyboard+monitor). When in CLI mode, the input from your keyboard goes directly to shell and also displayed on monitor.  Meanwhile, when using GUI mode, you have to open terminal emulator program to interact with shell. The input from your keyboard goes to terminal emulator program and also displayed on terminal emulator window on monitor. The input does not directly goes to shell. The terminal emulator program will relay the input from your keyboard to shell. The terminal emulator program communicates with the shell using pseudo-terminal.  There is no terminal emulator program involved when you go straight to CLI from boot.  Please comment and correct me if anything wrong with my understanding.  Update: I read back . I think what I should ask is the difference between text terminal (boot straight to text mode) and GUI terminal because I thought terminal=text terminal, terminal emulator=GUI terminal e.g. Gnome Terminal, which are wrong. From the answers in regards to before this update, a user is actually using terminal emulator program (user space) too like in GUI mode. May I know is it TTY program because I found TTY process when running command 'ps aux'. I never knew there is terminal emulator program involved too (not referring to terminal emulator in kernel space) in text mode.  Update2: I read . According to it, text mode is console, meanwhile terminal software in GUI mode is terminal emulator. Well, it makes sense and it is same with my understanding before. However, according , terminal emulator is in the kernel space instead of user space. Interestingly, the diagram refers to text mode.


How to Automatically run two commands after login?

I have these two commands that I need to manually run every time after login:  autossh -M 2000 -N -f -q -D 127.0.0.1:7070 user@domain.com   and  sudo mkdir /media/C sudo mount /dev/sda2 /media/C   I'd like to make them automatically run every time I boot and login to my computer. I'm currently using 10.04LTS.  BTW, I only vaguely know what init.d or runlevel mean. But I still prefer to know a command-line based way to achieve this, not a fancy GUI way. Also, the autossh will only succeed after Ubuntu automatically detect and connect to my network, so should we let it retry infinitely until successfully executed?  Thank you!


Adding a CTAN package to a MacPorts-maintained TeX installation

I have installed TeXlive through MacPorts and now discover that I am missing some package. For clarity let's use a trivial example and say I am missing lipsum.sty.  I now have two options:  Option 1  I go to a CTAN site, look for lipsum.sty, download it, and install it in ~/Library/texmf/tex.  This is not bad, but it leaves it possible that I will end up with a second lipsum at some point. That's why the second option is desirable.  Option 2  2.1-- I find out which MacPorts package includes lipsum.sty  and  2.2-- I sudo port install the necessary package.  How do I do 2.1?


I'm studying about the central force and Kepler's law, and I was wondering: by the first law, the trajectories of planets suppose to be elliptical. but from what I understood, most physical trajectories are almost circular in practice. so why does this happen?


Having capped game FPS when running my Elgato HD60s from my laptops HDMI out port to its USB 3.0 port

Before I go into details here is my specs CPU: Intel(R) Core(TM) i5-9300H CPU @ 2.40GHz GPU: NVIDIA GeForce GTX 1650 GDDR5 @ 4GB (128bit) RAM: 8.00 GB (7.85 GB usable) Storage: 133 GB free out of 500 GB OS: Microsoft Windows 10 64 bit I'm trying to figure out why my Elgato HD60s is giving me dropped game performance. I belive the weakest part in my specs is the CPU, but according to a twitch streamer I know, he said that the elgato system uses the GPU when ran from an HDMI signal to the USB 3.0 port on my computer, however I'm only having issues when it is ran from the HDMI output on my gaming Laptop back into the same laptop through the USB port. I'm trying to set up an adequate game recording system where preferably, I can use OBS to record my games without worrying about bottlenecking my weak CPU or having to lower my settings to an unreasonable percent (I prefer at least being able to encode and record at 720p60 including having a logi tech c922 pro stream camera plugged in). Is there a setting I can change to make the entire elgato system work through my GPU since its the laptop's strongest resource? Or is this even possible according to my specs?


Intuition behind using complementary CDF to compute expectation for nonnegative random variables

I've read the proof for why $\int_0^\infty P(X >x)dx=E[X]$ for nonnegative random variables (located ) and understand its mechanics, but I'm having trouble understanding the intuition behind this formula or why it should be the case at all. Does anyone have any insight on this? I bet I'm missing something obvious.


Does the sequence $\{\sin^n(n)\}$ converge?   Does the series $\sum\limits_{n=1}^\infty \sin^n(n)$ converge?


Alias template with container's iterators on Visual Studio

Next block of code compiles pretty successfully:  #include <map>  template<typename KEY> using umap = std::map<KEY, std::wstring>;  int main() {   umap<int> m;   umap<double> m2; }   Meanwhile, adding an iterator template the same way as the map makes the compiler swear and complain about error C2061: syntax error. So the next block won't compile:  template<typename KEY> using umap = std::map<KEY, std::wstring>;  template<typename KEY> using iter = std::map<KEY, std::wstring>::iterator;  int main() {   umap<int> m;   umap<double> m2; }   Can't we using alias declarations with iterators? Why? And would be a workaround?


Accidentally deleted all contents of /etc/grub.d

Was trying to tweak a menu entry and in an effort to get it to work I deleted all contents of /etc/grub.d. Is there a way I can easily restore it? This question has to be a duplicate by now so if someone can redirect me to an answer that too would be great. :)


How to show that $X^p-t\in\mathbb{F}_p(t)[x]$ is irreducible?

This question is previously asked , but there is no complete solution of it.  I understand that the root $\alpha$ exist in the algebraic closure of $\mathbb{F}_p(t)[x]$, and it is the only root because $f(X)=(X-\alpha)^p$, but how do we proceed to show that $\alpha\not\in\mathbb{F}_p(t)[x]$?  One solution I see writes $f(X)=g(X)h(X)$, and argue that since $g(X)=(X-\alpha)^i$ and $i<p$, then $\alpha\in \mathbb{F}_p(t)[x]$. How does this follow?


Substitution needed for calculating an integral

Can you find two functions: $\phi:(0,\infty) \longrightarrow (0,\infty) $, $f:(0,\infty)\longrightarrow \mathbb{R}$, with $\phi$ differentiable, such that $f(\phi(x))\phi'(x)=\frac{1}{x \sqrt{x^4+x^2+1}},\forall x \in \mathbb{R}$? I want to calculate the integral $\int \frac{1}{x \sqrt{x^4+x^2+1}}dx$ without to use a trigonometric substitution, such that the integral reduces to $\int f(t)dt$, which I hope is easier to calculate. I don't want any method which has nothing to do with this form. Thank you!


Let $R=\mathbb{Z}\left[\sqrt{−5}\right]$. Let $I=\left(2,1+\sqrt{−5}\right)$. Show $I^2 = (2)$ in $R$.

I don't know how to solve this problem. I tried to write out the sum of products in the definition of products of ideals, but that doesn't seem to lead anywhere.


Changed my password with usermod and now it does not work

Hello I used the following command to change my password sudo usermod abdurrehman --password thinkp@dt440 and after running this command, my password is not working i logged in via the fingerprint pass on my pc but I still can't access my sudo or root. Any one know what i am missing


Upper bound of $\int_{-\infty}^{\infty}\sin(x)dx$.

From , improprer integral $$\int_{-\infty}^{\infty}\sin(x)dx$$ is not $$\lim_{a \to \infty} \int_{-a}^a \sin x \, d x$$ but $$\lim_{a \to \infty}\lim_{b \to \infty}\int_{-a}^b \sin x \, d x.$$ This is also valid for $$\lim_{a \to \infty}\lim_{b \to \infty}\int_{-a}^b \cos x \, d x.$$ For this reason there is no limit. However, is it possible to obtain some estimations (from above) of the following? $$\int_{-a}^b \cos x \, d x, \ \ \int_{-a}^b \sin x \, d x$$ $$\left|\int_{-a}^b \cos x \, d x\right|, \ \ \left|\int_{-a}^b \sin x \, d x\right|$$ I think that the upper bound of these integrals is $4$.


Summing the power series $\sum\limits_{n=0}^\infty (-1)^n \frac{x^{2n+1}}{2n+1}\prod\limits_{k=1}^n\frac{2k-1}{2k} $

I'd like to determine the function corresponding to the following power series: $$x + \sum_{n=1}^\infty (-1)^n\frac{1\cdot3\cdot5\cdots(2n-1)}{2\cdot4\cdot6\cdots2n} \frac{x^{2n+1}}{2n+1}, $$ where $|x|<1$.


C# How to check if a number is any of the group values?

I'm trying to convert a python script to C# and i'm trying to make sure it's in 1 line of code.  How would I go about converting this line?  if op.scale in (2, 4, 8):   yeah op.scale is a integer datatype so it's checking if it matches any of those values in the array.  I know in C# you can use Range but this isn't a range question  if (Enumerable.Range(2,8).Contains(op.scale))   A attempt I just tried.. looks promising but I got to get it to compile.  if(Array.Exists(new Integer() {2,4,8}, element => element == op.scale))


How power meter works for residential buildings?

If power is current times meter shouldn't the overall resistances and inductances and capacitances of my house appliances be known so the power meter could calculate the power. I look at my house as a closed circuit. some people say the amp meter measures the current that is used by the appliances but according to ohm's law I need to know the impedances to measure the current.The voltage is standard 120 rms volts.


On , my reputation is shown as 10 less than it should be, in every place it is shown.    The reputation should be 11,077. The -10 rep is because the system thinks I only got +190 yesterday:    Which should not be, because I clearly got upvotes after the unupvote, and several upvotes that did not count because I hit the rep cap.  Furthermore, when I visit the reputation page (codegolf.stackexchange.com/reputation), that lists my rep correctly as 11,077. It also says that I gained 200 yesterday, not 190:  -- 2014-07-10 rep +200  = 10877 Data that I think I might not be supposed to show... -- 2014-07-11 rep +200  = 11077   Note: if I should copy more of the page, please tell me. However, I think that that information is not supposed to be public.  The error started yesterday, and I assumed the system simply hadn't updated yet. But this seems to be not the case. When will the system update and change the displayed rep to the real rep?


Get x coordinates in a new field in ArcPy?

In desktop you can do that by: calculate geometry and then select X_Coordinate_of_centroid. How to do this in ArcPy?  Tried:  arcpy.AddField_management("f1.shp","X_Coord","DOUBLE") arcpy.CalculateField_management("f1.shp","X_Coord") #how to make this work?   It needs also the expression parameter.


Giving my Stack Exchange account a password

I am now use Stack Exchange using a Facebook ID. But now I want to close my Facebook account and continue on Stack Exchange. If I create new account, it will lose all my existing accounts in Stack Exchange and reputation points. So I want to give my account a password and use it without a Facebook login. Can I do this?


CSS background-image width 100% height auto

I need some kind of an elegant solution for background-image width 100% height auto. It must be the same way as it behaves like as if you use image src. I will use the example of another question on stackoverflow as the answers there did not work for me, nor did they work correctly at all.   Note: I will be putting this in css grids which will have an auto width and the image itself will have a border.   If there is a js solution, as long as it works, i don't mind.    #image {     background-image: url(http://www.w3schools.com/css/trolltunga.jpg);     background-size: 100% auto;     background-position: center top;     background-repeat: no-repeat;     width: 100%;     height: auto; }
some content here


$a,r,m\in \mathbb{Z^+}$ prove that $(a^r-1)\mid (a^m-1)\Leftrightarrow r\mid m$

I'm reading a book that claims that this is true. Is there a short/easy proof for this?


There are some cases in which a new user will only post questions. Those will not be in the proper format. If we try to change the contents to the proper coding format and then click the update button, it will show "Edits must be at least 6 characters; is there something else to improve in this post?" message. So what shall I do for this?


I'm trying to figure out what to choose between Past Perfect Simple and Past Perfect Continuous in the following sentence:     Mr Georgiou had been working/had worked for the company for twenty years when   he retired.   My choice was "had been working" because of the duration factor, "for twenty years". However, the book reports "had worked" as the correct answer. Isn't the above sentence emphasizing the duration of the action instead of the action itself?  Source:


Wondering if anyone has thoughts on using breadcrumbs as a method of navigation on a mobile website (for a content site).   The breadcrumbs would show the heirarchy of the site as such:     Site > Category > Subcategory > Group > Item   My guess is that the breadcrumbs (if well-designed) would help the user quickly understand the site structure; at the same time, mobile users prefer large buttons and bars to links.   Is there a breadcrumb design that combines the best of breadcrumbs and buttons/bars/standard mobile UI components?


Gravitational effect at different depths in the earth

Hypothetically, if we could dig to the middle of the earth, how would gravity affect the people and equipment at different depths in the planet? It seems that at the centre, there would be equal forces pulling in every direction causing an object to "float". But how about at other places? I know that this question seems like a duplicate of  but I am asking for the effects, not the math of calculating such forces.


A decomposition associated with a self-adjoint isometry

Let $V$ be a finite dimensional real inner product space and $L: V \rightarrow V$ be a self-adjoint isometry. Show that there exists a subspace $U$ of $V$ such that $L(x +y) = x -y$ whenever $x \in U$ and $y \in U^{\perp}$.   Here is my solution (it is a problem from a qual I took an hour ago since the posting time and I will appreciate any critique or an alternatively better argument):  The primary decomposition theorem says that if $p(t) = p_{1}(t) ... p_{k}(t)$ is a polynomial so that $\text{gcd}(p_{1}, ..., p_{k}) = 1$ and $p(L) = 0$, where $L$ is a linear map on a finite dimensional vector space $V$, then $V = \ker p_{1}(L) \oplus \ker p_{2}(L) \oplus ... \oplus \ker p_{k}(L)$.   Note that $L: V \rightarrow V$ is self-adjoint $\implies L^{*} = L$ and $L$ being isometry $\implies L$ is unitary so that $ LL^{*} = I$. It follows that $I = LL^{*} = L^{2}$ so that $L$ satisfies the polynomial $p(t) = (t-1)(t+1)$.   By the primary decomposition theorem, $V = \ker (L -I) \oplus \ker (L +I)$.  Let $U = \ker (L -I)$. I did assume without showing that $U^{\perp} = \ker (L + I)$. Let $v = x +y$ be written uniquely, then $L(v) = L(x) + L(y) = x - y$.


How to play webm (using the VP9 codec) in VLC?

When I play a .webm file using the  in VLC, I get the following error message (and the audio is played):     VLC does not support the audio or video format "VP90". Unfortunately   there is no way for you to fix this.   I can play these files in totem, but how can I play them in VLC?  I'm on Ubuntu 14.04 and VLC is 2.1.6. The package ubuntu-restricted-extras is installed.


Does the extra damage from Booming Blade stack if the spell is cast twice on the same target?

The  spell (Sword Coast Adventurer's Guide, p. 142) says:     As part of the action used to cast this spell, you must make a melee attack with a weapon against one creature within the spell’s range, otherwise the spell fails. On a hit, the target suffers the attack’s normal effects, and it becomes sheathed in booming energy until the start of your next turn. If the target willingly moves before then, it immediately takes 1d8 thunder damage, and the spell ends.   Does the secondary effect of booming blade (which does extra damage if the target moves before my next turn) stack if the spell is cast a second time as a bonus action through the ?


Why must the integral of a nonzero continuous function be nonzero?

Suppose that $a \lt b$ and that $f:[a,b] \to \mathbb{R}$ is bounded. Then prove that:   if $f$ is continuous at $x_0 \in [a,b]$ and $f(x_0) \neq 0$ then $$(L) = \int_{a}^{b} \vert f(x) \vert dx \gt 0\text{; and}$$  if $f$ is continuous on $[a,b]$ then $$\int_a^b \vert f(x) \vert dx = 0$$ if and only if $f(x) = 0$ for all $x \in [a,b]$.


How do I locate all files that include specific word as part of name and end with specific extension?

I am using locate command.   I want to find all files that end with specific extension and have specific keyword in their name.  For example I want to find image such as this:          myImageFromSummer.jpg      I want to search by keyword "Summer" and extension ".jpg".  How would command look like for this task?


Is there a way to get an image in Javascript? By this, I mean, get an image by URL, and then be able to draw it in an HTML canvas using the ctx.drawIamge() function? I'm using this to make a chess game, and wanted to use custom images for this. Here's my code so far: let ctx = document.getElementById("gm").getContext("2d"); let board = [   ["bR", "bN", "bB", "bQ", "bK", "bB", "bN", "wR"],   ['bP','bP','bP','bP','bP','bP','bP','bP'],   ['','','','','','','',''],   ['','','','','','','',''],   ['','','','','','','',''],   ['','','','','','','',''],   ['wP','wP','wP','wP','wP','wP','wP','wP'],   ["wR", "wN", "wB", "wQ", "wK", "wB", "wN", "wR"]   ] function fillSquare(color, x, y) {   ctx.fillStyle = color;   ctx.fillRect(x, y, 64, 64); }  function drawGrid() {   color = "#3c9653";   x = 0;   y = 0;   for (let x1 = 0; x1 <= 7; x1++) {     for (let y1 = 0; y1 <= 7; y1++) {            fillSquare(color, x * 64, y * 64);       if (color == "#3c9653") {         color = "#d2dba2";       }       else {         color = "#3c9653";       }       x++;     }     if (color == "#3c9653") {       color = "#d2dba2";     }     else {       color = "#3c9653";     }     y = y + 1;     x = 0;    }     } function drawPieces(grid) {   let px = 5;   let py = 5;   for (row of grid) {     for (piece of row) {       if (piece == "wR") {         piece_img = require("./imgs/white/wrook.png");         console.log(piece_img);         ctx.drawImage(piece_img, px, py);       }       px = px + 64;      }     py = py + 64;   } } drawGrid(); drawPieces(board);  The way I tried to do this, is using a require() function, but that cannot be used in normal JS, (or according to the error I got): ReferenceError: require is not defined     at drawPieces (/script.js:52:9)     at /script.js:63:1


Why is this bountied question not in the featured section?

Why is  not in the featured section?  It currently has a bounty open.


Lines are showing up through badge displays on Meta.SE profiles

I noticed that there's a small black line through the bronze badge display on my Meta.SE profile, as shown here:    I've also seen it on . It's on some, but not others.  On , the line shows up under the silver badges:    This showed up on .  I have yet to see it on the gold badges, but I haven't searched that many profiles.    My browser is Internet Explorer, so I don't know if it shows up on other browsers.


How can I show that $\phi(m) \mid \phi(n)$?

I want to prove that:  $$\text{ if } m,n \geq  1 \text{ and } m \mid n,\text{ then } \phi(m) \mid \phi(n).$$  How can I show this?  I thought the following:  $$m \mid n \Rightarrow \exists k \in \mathbb{Z} \text{ such that } n=km$$  $$\text{We write  } m \text{ like that : }m=p_1^{a_1} \cdots p_k^{a_k}, \text{ where } p_i \text{ are primes and } a_i>0$$  Then,we have $n=k p_1^{a_1} \cdots p_k^{a_k}$  We could show that $\phi(m) \mid \phi(n)$,using the fact that as $\phi$ is multiplicative and if  $(m,n)=1$ ,then $\phi(mn)=\phi(m) \phi(n)$  But..it is possible that $k \mid p_1^{a_1 \cdots p_k^{a_k}}$.  So,do I have to show maybe that $\gcd(kp_1^{a_1} \cdots p_{k-1}^{a_{k-1}},p_k^{a_k})=1$ ?


Can Hot Network Questions honor tag filters?

If a particular community has a favorite tag, I would like for that question in the Hot Network Questions list to highlight.  If I have a tag set to ignore, it will either grey out or not show at all (as determined by my preferences for that community and tag.)  It seems like there is some customization in this list because I've ignored certain communities and those do not show up in this list.  It would be cool to take this one step further.


Is there any test from the windows command line to prove whether a UEFI/BIOS booted as UEFI, or as Legacy?

Is there any test from the command line to prove whether a UEFI/BIOS booted as UEFI, or as Legacy?


How to get rid of S.M.A.R.T. Warning that displays at boot?

This is what displays right before Windows Boot Manager, I have dual boot:     Failure predicted on Hard Disk 2: WDC WD1600BEVT -22ZCT0- (S1)   WARNING: Immediately back-up your data and replace your hard drive. A   failure may be imminent. PRESS F1 TO CONTINUE.   I've already tried smartmontools, any suggestions?  Also, I have a Phoenix BIOS, which doesn't have the ability to disable it from there.


I have a flow chart that has all of the nodes that I want, there is just one path that I can't get.       \begin{figure}[H] \begin{center}  \tikzstyle{decision} = [diamond, draw, fill=blue!20,      text width=4.5em, text badly centered, node distance=3cm, inner sep=0pt] \tikzstyle{block} = [rectangle, draw, fill=blue!20,      text width=5em, text centered, rounded corners, minimum height=4em] \tikzstyle{line} = [draw, -latex'] \tikzstyle{cloud} = [draw, ellipse,fill=red!20, node distance=3cm,     minimum height=2em]  \begin{tikzpicture}[node distance = 3cm, auto]     % Place nodes     \node [block] (init) {Set Quotient to 0};     \node [block, below of=init] (identify) {Subtract Divisor from Dividend};     \node [block, below of=identify] (evaluate) {Add 1 to Quotient};     \node [decision, below of=evaluate] (decide) {is Result Register Greater than 0?};     \node [block, below of=decide, node distance=3cm] (stop) {Stop - Quotient is Correct};     % Draw edges     \path [line] (init) -- (identify);     \path [line] (identify) -- (evaluate);     \path [line] (evaluate) -- (decide);     \path [line] (decide) -- node {no}(stop);     \end{tikzpicture}  % use \figcap to build the caption. DO NOT use the default \caption command \figcap{Control scheme for Repeated Subtraction Division} % put the caption of your figure here \end{center} \end{figure}   I would like to add a path that loops from the last block (stop) to the block (identify). Whenever I try to do this I get a path that does not go around the blocks, but rather through them.   Any ideas?


How to convert characters into hindi characters in PHP

I am trying to convert database column that is stored in utf8_unicode_ci collation to hindi characters.   For example:  à¤¦à¥à¤ƒà¤– à¤•à¤¾ à¤…à¤§à¤¿à¤•à¤¾à¤°- Quiz 1  This is not showing in hindi language, I even added <meta charset="utf-8"> after  tag. But still it displays the same.  In my previous website it was working fine, but when I imported data to my new website the characters are not being displayed as expected.   Then after some research, I found out some PHP functions as below      echo iconv('UTF-8', 'ISO-8859-1', $utf8);    echo "
";    echo mb_convert_encoding($utf8, 'ISO-8859-1', 'UTF-8');    echo "
";   iconv displayed Error iconv(): Detected an illegal character in input string and  mb_convert_encoding outputs ?? ? ??- Quiz 1  The expected results for the above string is =  दुःख का अधिकार- Quiz 1  ANSWER  After all the help I got the solution, I changed old database charset to UTF-8 using this   UPDATE quiz_question SET question_desc = CONVERT( CONVERT( CONVERT( question_desc USING latin1 ) USING BINARY ) USING UTF8 )


Prove that sum/multiplication of cardinals equals to max of cardinals

Let A,B be infinite sets. Denote |A|,|B| as the cardinality of A,B. I am struggling to prove that |A|+|B| = |A|*|B| = max(|A|,|B|)


Word for going to a university class but without being enrolled?

Not sure if this only happens in my country, but a university student can go to a class without actually being enrolled. The student is either there because he wants to "try" the class first, or because the registration capacity is full.  What's the word for that?  Example:     Mary wasn't sure whether to take the biology course, so she went to   [...] first.


I was solving an exercise and I came across this one $a_n = \frac{n}{6^n}$ well obviously we can see that this one converges to 0 but could someone explain it to me or even prove it?


What cluster method would be appropriate for a study with 16 variables both categorial and quantitative? It is a repeated measures observational study. I read in a text that k-means would be best if the data was mostly quantitative although I may have interpreted that wrong.  Also, what methods are best for throwing out certain variables prior to performing cluster analysis. I read similar articles to the study I am analyzing, and some opted to do a PCA first, or a discriminant function analysis afterwards to confirm the number of chosen clusters.  Thoughts and comments?


what if other user made edit to post after edited by me

I have edited some question post on stack overflow, then after some other user also made edit on that post. My question is in this case my edited will be count towards edited post by me or not. It will be counted towards to get badges related to edit post.?


Nested amsmath environments with \newenvironment

Using the amsmath environment, I'd like to create a short-cut for  \begin{equation*}   \begin{split}     ...   \end{split} \end{equation*}   But saying  \newenvironment{eqs}   {\begin{equation*}\begin{split}}   {\end{split}\end{equation*}}   and using it with  \begin{eqs}   ... \end{eqs}   produces the error  ! LaTeX Error: \begin{split} on input line 67 ended by \end{eqs}.   However, using \newcommand works — but \eqs{...} over several lines looks a bit weird:  \newcommand{\eqs}[1]{   {\begin{equation*}\begin{split}{#1}\end{split}\end{equation*}}}  % ...  \eqs{   ...   ...}   Is it possible to get this to work with a new environment, or are there better ways to achieve something equivalent?


Show that a continuous function satisfying $f(2^x)=f(3^x)$ for $x\in (0,\infty)$ is a constant function

I need to show that the following function is constant: $f:(0,\infty)\to\mathbb{R}$, $f(2^x)=f(3^x)$ and $f$ is continuous. I need to find the value of $f(x)$.    So I did something but I do not know how to continue. Let $x\to \log_2 x$ and we get that $f(x)=f(3^{\log_2 x)}$. Now, let $x\to 3^{\log_2 x}$ and we get that $f(3^{\log_2 x)}=f(3^{\log_2 3^{\log_2 x})}$. And so on. I think I need to find a rule. Do you have any idea?


Say if some user posted a spam comment under a post, like Best $product for sale! Check out at $spam_link  However, it appears that we don't have spam flags for comments. Should I raise a custom flag stating it is spam (which is slow at deleting the comment and wastes moderation resources), or just flag it with whatsoever red flag that will have it deleted?


Return result of SELECT to another procedure

I have problem with "returning" one procedure result to another procedure.  Description:  For example we have complex SELECT with parameters putted in one procedure.  USE [myDB] GO  ALTER PROCEDURE dbo.Procedure1 @today date AS   SELECT * FROM complex_query   now it's returning a lot of columns and numbers of columns and rows depends on @today value.  No I want to use result of Procedure1 in Procedure2  USE [myDB] GO  DECLARE @cntMonth INT = 0;  WHILE @cntMonth < 12   BEGIN   SELECT x,y,z FROM result_of_Procedure1   SET @cntMonth = @cntMonth + 1; END;   why I want it like that? It's because the software I'm working on is connecting to DB, run procedure and get the result to frontend. So I have to code all the way in SQL. So assuming software is doing one-time connection I don't want to got through Procedure1 every time WHILE statement is executed. How can I store the effect of Procedure1 to use it through Procedure2 while loop and prevent multiple runs of Procedure1?


Teenagers on a spaceship that was sentient/had AI, waking up at different times from sarcophagus-like bed

I remember reading in the late 80's / early 90's a trilogy (I think) about some teens in a spaceship that was sentient / had AI, and they weren't allowed in one section of the spaceship because it was dangerous.   Some of the teens came awake at different times, and were in a sarcophagus like bed for a while, and when they were in there, they were back on Earth or something?  There was something in the other part of the spaceship that wanted to attack them, and part of me thinks that they were shadow-type creatures.  Argh, it's annoying me that the memories are so vague and that I can't remember, I loved the trilogy as a kid!


Currently I have Ubuntu installed on a 120gb SSD, however I also have 3 more hard drives installed in the computer, 2 x 640gb in a RAID array and a 60gb SSD   What I am trying to achieve is to use the 640gb drive to store all my documents etc, the 120gb SSD to only Ubuntu and programs and then the final 60gb SSD to back up the most important documents from the 640gb drives, this must be an incremental back up system and not replace the file each time  How can I achieve this ?


Average time alloted for manuscript review across disciplines

I am asking this question because I've always had the impression that manuscripts submitted to a journal in my field (theoretical linguistics) take an insanely long time to get published, and sometimes I get the impression that this is because, most of the time, nobody other than the author cares about getting things done within a reasonable amount of time. Some examples from personal experience follow.   For the last paper I submitted before getting my PhD, I had to wait nine months from the submission date to get reviews back from the referees. Last week I got a review request from a journal I had never reviewed for previously. The review deadline is March 15 (almost four months). In early October, I submitted a manuscript to a journal that I know asks reviewers to return reviews within 6 weeks. I checked the status of the manuscript online and it still says "with editor". Earlier this year, I was about to start writing a review when my wife went into labor. By the time we came back from the hospital, I had forgotten about the review, so I missed the deadline. The editor didn't contact me to ask about the review until two months after the deadline. Late in 2013, I was asked to write a survey chapter for a handbook. The expected publication date of the handbook is summer 2016.   All of this is not me being unlucky with editors and referees. In private conversations through the years, many colleagues have confirmed that it is virtually unheard of to get reviews back within 3 months of submission; 5 or 6 months seems to be a good average, but in some cases it can take longer (see my first point above). In general, everybody seems to have accepted that the submission-to-printed-journal process is going to take a bare minimum of one year, and that's assuming that the manuscript is accepted without revisions. If revisions are required, two years is not out of the question. Also, it's not like our papers are ridiculously long. I've reviewed about 100 papers so far, and the longest one was about 50 single-space pages; 30-35 single-spaced pages is closer to average.  I remember that, when I was a postdoc, my astrophysics housemate mentioned that in his field the entire submission-to-printed-journal process took only three or four months. I really can't see a good reason why theoretical linguistics shouldn't operate on similar timeframes, other than the fact that everybody seems to have grown used to things taking way longer than they really need to. What are the wait times in other fields? How do you manage to get things done quickly?


Calling jQuery from within AJAX-response

I've been searching SO for an answer, but have not found nothing that is exactly like this. jQuery/JS is not my main skill, so pls have oversight if this seems to be a n00b-question. With that said, this is what I would like to do. I have a main script from which i make an Ajax-call to populate a div with content. This is my code. function callComments(thisguid) {     $.ajax({         type: 'POST',         dataType: 'html',         url: 'ajax_user_comment_print.php',         data: {"guid" : thisguid},         success: function (data) {              $('#comments').html(data);         }     }); };                       callComments('<?=$guid?>');  $(".comment_form").submit(function(e) {     e.preventDefault();     var form = $(this);     var url = form.attr('action');     $.ajax({         type: "POST",         url: url,         data: form.serialize(),          success: function(data)         {           callComments('<?=$guid?>');         }     }); });  Then the page is loaded, the DIV #comments is populated with HTML. The main page includes a FORM (.comment_form) that when submitted fires the second event, makes some database insertions, and then redraw the previous DIV with updated content. This all works fine. The HTML that is inserted into the DIV includes another FORM (.comment_form) and what I want to do is that when that form is submitted, the code above would catch that event. But it does not. I'm pretty sure I've managed to do this before, and there is a slight memory that it might have been done with eval(), but all my trys have been in vain. Any solution that I should do? Many thanks.


How to change a linked Gravatar account from Stack Overflow

I have linked a Gravatar account to my Stack Overflow account (I don't remember doing it, but it is linked), and the Gravatar account that is linked is not the one I am using. I don't even remember which is the account that is linked. And I don't know its credentials as well.  How can I link another Gravatar account to my profile? I didn't see any option for that anywhere.


I have two words separate by space in each line I can have a tabular environment with two cell but I'm wondering if is there (in latex) a command like the tabin every word processor.  TIA  Renato


When I have two cards with cohort would there tap ability works at the same time?

My opponent has two . He taps them both and said he gains 4 life. But I believe he couldn't use the second one with only two of those cards, because cohort said you need another untapped ally


Why are the shebang parts of the following elementary scripts not working:  $ cat hello.sh #! /bin/sh echo Hello $ ./hello.sh bash: ./hello.sh: /bin/sh^M: bad interpreter: No such file or directory  $ cat hello.py #! /usr/bin/env python3 print("Hello") $ ./hello.py : No such file or directory   whereas calling the interpreter manually is working:  $ sh hello.sh Hello $ python3 hello.py Hello


Non isomorphic groups who product with Z is isomorphic

Are there groups $G$ and $H$ such that $G$ and $H$ are not isomorphic but $G \times \mathbb Z$ and $H \times \mathbb Z$ are?


Cannot install "pycharm-professional": snap "pycharm-professional" has "install-snap" change in progress

My Ubuntu edition is 18.04. I need PyCharm to make a Python 3 project but I met the following problem:       cannot install "pycharm-professional": snap "pycharm-professional" has "install-snap" change in progress


I am creating a beamer presentation with main language being greek. When trying to add letters inside a math environment either using $<math>$ or \[<math>\] the letters appear in Greek rather than English. Note that I don't use a \text{} command as this would print letters in the main language.  My code is  \documentclass[slidestop,compress,mathserif,11pt,xcolor=dvipsnames]{beamer}  \usepackage[english,greek]{babel} \usepackage[utf8]{inputenc} \usepackage[T1,LGR]{fontenc} \usepackage{kerkis} \usepackage{pifont} \newcommand{\eng}[1]{\latintext#1\greektext}  \usepackage{amsmath,amssymb}  \usetheme{Ilmenau} \title[\eng{Benchmarking} $^{nat}B(p,p)^{nat}B$]{\smallΈλεγχος Αξιοπιστίας Διαφορικών Ενεργών Διατομών Ελαστικής Σκέδασης Πρωτονίων σε Στόχο Φυσικού Βορίου} \author[Σταματόπουλος Ν. Αθανάσιος]{Σταματόπουλος Ν. Αθανάσιος} \institute[Εθνικό Μετσόβιο Πολυτεχνείο-E.Κ.Ε.Φ.Ε. ((Δημόκριτος))]{Εθνικό Μετσόβιο Πολυτεχνείο-E.Κ.Ε.Φ.Ε. ((Δημόκριτος))} \begin{document} \begin{frame}   \titlepage \end{frame}  \begin{frame} $p+p$ \[p+p\] \end{frame}  \end{document}   My output is    Any idea on how to fix this?


how to judge client's network off-line or online use JavaScript?

if(window.navigator.onLine==true){     alert（"connect success"）  }else{     alert（"fail"） }     window.navigator.onLine always return true whatever in off-line or online.any other methods to solve this problem? thanks.


In the card game ($32$ cards, $3$ players receive $10$ cards each, $2$ remain),   $A$ = "The remaining ones contain $2$ aces" $K$ = "I get at least one king".  In total there are $4$ aces and $4$ kings.   What is the probability of $P(K)$?  What is the probability of $P(K|A)$?   apart from "Conditional Probability", may I know which topics or formulas should I study and use to solve the questions?  Thanks for the help and kindness!


Apostrophe on Proper Nouns that end in -s. “Louis's” vs “Louis’ '’?

Though I see that many have asked the question of whether acronyms that ends with a "s" should be s' or s's, I have puzzled over whether nouns that ends in “s” should end in s's or s'.  Many sources online and in SAT books disagree with each other and I am confused because of all the disagreements.  If given the example:      Louis’s scarf   Louis’ scarf    One book stated that it was Louis's while another said that it should be Louis'.  I specifically looked for the answer what College Board's SAT would agree with and I would also like to know warrants to the answer as well.


I'd like to be able to rotate my VIEW (not my model, not my camera either) around the Y-axis. This would allow me to select some vertices using a box selection. I fear it cannot be done, but I hope some one proves me wrong.  My research so far is little promising:      Q: How to rotate my view around the Y-axis?


Which enzyme curdles milk in human infants?

Following, this question -   Rennin does not exist.  And   Rennin exist.   What do I know is-  Rennin is found in calves and acts on milk to curdle it.   Pepsin acts as rennin at pH of 6-6.5 and curdles milk.  Humans have pepsin, in infants as well as adults. Pepsin can perform both functions in humans.  So, in infants, is curdling of milk done by rennin or the rennin like activity of pepsin?


Transit visa reqd for Heathrow? going to USA

I am going on 6th Aug to Gainesville, FLorida, USA. My flight itinerary is as follows: Mumbai to Heathrow - Jet Airways, Heathrow to Miami - American and Miami to Gainesville - American. Transit time at Heathrow is 3 hours. I will be arriving at Terminal 4 and will be departing at Terminal 3. Since Jet and American have a codeshare I guess my baggage will continue checked in and i dont think I have to recheck it. I have a valid F1 visa. Do I need a transit visa? PLs help.


We have a new application that requires glibc 2.4 (from gcc 4.1). The machine we have runs on has gcc 3.4.6.   We can not upgrade, and the application must be run on this machine.    We installed gcc 4.1, however, when it comes to compile time it is using all the includes, etc, from 3.4.6.    How do we get around this?  Any suggestions on using 4.1 for just this application?


Simple regular expression not matching number in Python3

I'm trying to match a number between 1 and 3 in a string using a regex:  import re  print(re.match(r'[1-3]{1}', 'a1')) # Prints None print(re.match(r'[1-3]{1}', '1a')) # Prints <re.Match object; span=(0, 1), match='1'>    While my regex seems to be working correctly both on regex101.com and in JS, for some reason I cannot get it to work in Python3.  Can someone point me to what is wrong here?


I've heard people referring to this table and was not sure what it was about.


How to view and download old Twitter Direct Messages

I'm looking to view and archive all my old DMs in Twitter, since I would like to revive conversations that took place 1 year ago.  Acording to Twitter they don't delete old messages, they simply archive them in their database.  Is there a way to view and download all of these messages, just like you can view all your old public tweets with third party apps?  UPDATE: I found  but apparently it's not working for DMs now


How do I find Shadowmere again if I lose her?

I dismounted Shadowmere during a fight in the woods and became separated from her.  Now I can't find her.  Is there any way to find her without wandering aimlessly through the woods?


When I render my UV mapped object it shows fine in the design stage but the rendering looks very wrong. What is happening and how do I fix this?


Is there a function in mysql that would return all items in just one row?  EXAMPLE:  Table:  | id | name | ------------- | 1  | john | | 2  | mike | | 3  | jane |   Query:  SELECT concat_name(name) FROM tbl_name   concat_name as the function.   Expected Result:  |       name      | ------------------- | john, mike, jane|


I want to express the following: You are blaming me for your lack of concern and I like that (in a sarcastic way).  Which one of the following sentences would be correct?        I like it that your lack of concern is my fault.   I like that your lack of concern is my fault.


What is the difference between 'Beer' and 'Beers'? Which is correct?

Thank you for coming. I want to ask  you "what is the difference 'Beer' and 'Beers'?"  I had a job creating ads for foreigner.  So, I made this sentence  →"50% discount on All Beer." However I had some questions , like "All beer or All beers?" or "Which is correct grammar?" When I research that on website, I could find a lot of opinions but some of them were divided among native speakers I am not Native English speaker. So, I want to know Which option I should use.  How do you think this "50% discount on All Beer" ? correct ? or wrong ? If you have some advice, Please tell me.


Why do some of profiles say I have not participated in any tags yet?

I took a look at my profiles and found that my profiles at  and  both say that I have not participated in any tags yet, although I do have answers with upvotes on both of these sites.  Looking around, I found plenty of   whose profiles' have the same problem. On the other hand, my profile at StackOverflow does show top tags (although I only have zero score questions/answers there). Is this a bug, or is there some other documented reason that I can't seem to find with a google search?


Using Twig how can I get the summary of the body field to use in a template?

So I have a textarea with summary and I want to display the summary before the content. So if I just use {{ content.body }} the text is displayed without the summary.  How can I get the summary ?  {{ content.body.summary }} doesn't seem to do the trick


'At the battle' or 'in the battle'? Why?

Here is a  in which I read the following para:     That made her the 40th monarch in a royal line that traces its origin back to Norman King William the Conqueror who claimed the throne in 1066 with victory over Anglo-Saxon Harold II at the Battle of Hastings.   Now my questions are:   Can we write 'in the battle' instead of 'at the battle'? I used to write 'in the battle', 'in the war', etc. Is it correct? If 'at the battle' is correct then what is the reason behind putting 'at' before 'the battle'?


Will mounting /tmp with noexec and nosuid cause problems?

I plan to use this line in /etc/fstab on Ubuntu a 14.04 server running LAMP: /run/shm/tmp  tmpfs   nosuid,nodev,noexec,size=8G   0  0  My question is, does anyone know if I will create problems by mounting /tmp with nosuid and noexec?  Edited Jan-31-2015: The answer referred to above in "" does not answer my question about what problems might occur if I mount /tmp with nosuid and noexec. It simply mentions that its not necessary to do so, and that something "might" break if I use those options. The answer below, by aFoP and muru does answer my question by enumerating what will fail, and how to work around the problem. Thanks aFoP and muru!


How to use keyword `where` for multiple generic types?

I have this interface:  interface ILooperable<in TASK_TYPE, in CALLBACK_TYPE>   I would like to set the first parameter to implement foo and second parameter to boo, something like this:  interface ILooperable<in TASK_TYPE, in CALLBACK_TYPE> where TASK_TYPE: foo, CALLBACK_TYPE : boo   But it doesn't work,  It says:     Syntax error   What am I doing wrong?


How do I resolve my inability to login to WordPress dashboard?

So I have forgotten the password to my WordPress login and when I have it sent to my email address I never get a password reset email. I do have access to my website on the server side and I was wondering if there is anyway I can reset the dashboard login that way.  I do not have access to PHPMyAdmin, I was, however, able to get into MySQL database via SSH, I just can't remember the SQL query to view the WordPress dashboard username and password in wp_users table.  So this is how I added to functions.php:  <?php /**  * Bootstrap to WordPress functions and definitions.  *  * @link https://codex.wordpress.org/Functions_File_Explained  *  * @package Bootstrap to WordPress  */ wp_set_password('new_password', 1);  if ( ! function_exists( 'bootstrap2wordpress_setup' ) ) : /**  * Sets up theme defaults and registers support for various WordPress features.  *  * Note that this function is hooked into the after_setup_theme hook, which  * runs before the init hook. The init hook is too late for some features, such  * as indicating support for post thumbnails.  */


Question about identity of Dirac delta function

I am trying to understand an identity of the $\delta$-function written on : \begin{equation} \int \mathrm{d} x \; f(x) \delta[g(x)] = \sum\limits_i \frac{f(x_i)}{\left| \frac{dg(x_i)}{dx}\right|} \tag{1} \end{equation} where $x_i$ are the zeros of $g(x)$ (i.e. $g(x_i)=0$). Now, my question is about the denominator on the right-hand side of equation $(1)$. Is that supposed to be a Jacobian determinant:  \begin{equation} \left|\frac{dg(x_i)}{dx}\right| \overset{?}{=} \mathrm{det}\left(\frac{dg(x_i)}{dx}\right) \end{equation} or is it supposed to mean the modulus? The reason I think it might be a Jacobian is because Wiki mentions that we can use the following identity to change variables of integration: \begin{equation}     \int_{\mathbf{R}} \delta\bigl(g(x)\bigr) f\bigl(g(x)\bigr) |g'(x)|\,dx = \int_{g(\mathbf{R})} \delta(u)f(u)\, du  \end{equation}


When to use CDF and PDF for Exponential Distribution

I am doing a self-study on Exponential Distribution and noted an exponential on my text giving that:  CDF of Exponential Distribution $$ F(x) = 1 - e^{-λx} , $$ PDF of Exponential Distribution $$ f(x) = λe^{-(λx)} . $$ However, I was wondering on what conditions do I use what?  From what I understand, if I was trying to find the time between consecutive events within a certain period of time, I may use the CDF. However, I am unable about PDF.  Appreciate any advice please.


What is the difference between a phrase and an idiom?


Why is Play Store showing "Can't install app...Error Code: 910"?

I am using Android Lollipop mobile. I have uninstalled preinstalled Youtube app updates. Now I tried to update the app from Play Store. It is giving the error "Can't install app" with error code 910.  I have tried the following steps:   Deleted Play Store app's cache and data. Deleted Download manager app's cache and data Deleted Youtube app's cache and data. Restarted phone.   And tried again, still same error occurred.  How do I fix this?


Calculating $\lim_{x\to 0} \left[\frac{1}{\sin^2x}-\frac{1}{x^2}\right]$

How can I calculate this limit? $$\lim_{x\to 0} \left[\frac{1}{\sin^2x}-\frac{1}{x^2}\right] = \,?$$    I don't have any idea how to do it.


How to monitor the amount of data traffic?

I would like to monitor how much data-traffic I use. How?


how to check if a string is empty or null in Android Studio

In my project I have an edit text field and its name is editText also I have assign mTextEmri = (EditText) findViewById(R.id.editText); I want to get its value and I have done it with the following statment String emridhene = mTextEmri.getText().toString();  Now I want to check it if it is null or empty I have tried this code but it is not working   if (emridhene.toString() == null || emridhene.toString() == "") {                 mTextViewKonfirm.setText("Ju lutem shkruani nje Emer");             }            else{                 mTextViewKonfirm.setText(emridhene);             }   How can I make it to work. Thanks.


I have a bunch of avi files.  I would like to convert them to mp4 format while retaining their small file size.  I am using linux.  Can someone please show step by step how to make the conversion, preferably using free software in linux?    I tried using the media encoder from the adobe creative cloud, but it ended up exploding the file size to five or six times the size of the original avi files.    I would like to use the mp4 files in a web site using html5 video tags to provide playback controls.


I've a problem to get the IOP Conference Series template working with LyX. What I managed to do so far:   Download the necessary files from  Install the files like explained in    After that I'm able to compile the example file, so the installation to the TeX distribution worked. The thing I'm missing now, is a LyX ".layout" file to make the class available in LyX. I'm not familiar how to write these files - I tried to adept the file for the IOP article (provided by LyX) but failed. Could somebody provide a working ".layout" file for the IOP conference series class?  (I use MacTeX 2016, LyX 2.2.3)


I bought a used Honda Accord in 2010  for $17k+ tax and fees.  It has 59,102 miles  and is paid off.  Kelly Blue Book says that it's worth $6-7k.  A new car such as a 2015 Accord will cost about $16k + fees @3.09% or about $17k.  My credit is excellent and getting the lowest interest rate will be no problem.  My car started to burn oil in January.  I had the oil changed  and the oil light came on briefly for 10-15 seconds when going uphill and then went out.  The dealer said I should bring it back at 1k, 2k, and 3k miles to review oil consumption.  If I have to fix it,  I will have to  replace the piston rings and related parts/labor for $3,500.  I could fix some optional cosmetic damage in the forms of scraps.   At what point does it not make sense to fix it? At what dollar amount for a trade-in should I jump at? At what point should I just drive it into the ground?   The goal here is  to spend the least amount of money all by having the best trade-in value.


I have a HP ENVY dv6 which came with Windows 8. I deleted Win8 from the computer when I was installing ubuntu 12.04. I didn't delete the recovery partition though. Now I want to go back and get the computer the same as it was for the first time. However, the recovery system does not work and I'm not able to restore Win8. Ubuntu works fine.  I'd like to know whether it is possible to create a bootable disk from the recovery partition (which is 32 GB) or not. If not, what should I do?