If X and Y ~ Uniform(0,1), what is the distribution X/Y?

Given that $X$ and $Y$ are random variables drawn from a uniform distribution between $0$ to $1$, i.e. $$ X \sim Uniform(0, 1) \\ Y \sim Uniform(0, 1)$$ And given that $Y \neq 0$, what do we know about $\frac{X}{Y}$? What is it's distribution, PDF, mean, and variance?


How can I add dynamic content to the Ubuntu panel?

I want to change the clock on the Ubuntu panel into something more exotic. I am interested in finding a way to add an icon to the panel and be able to change it (like Psensor and Slack applications do, see picture) based on time or some other conditions.      When googling for this I've always gotten the response for the launch icons, and not the Ubuntu panel. I'm using Ubuntu 16.04  I've got the ide from Destin from Smarter Every Day YouTube channel, and I've made the second image in GIMP.


What is average distance from center of square to some point?

How can I calculate average distance from center of a square to points inside the square?


Add pagination to the posts retrieved by below query

I am trying to show all published posts of my custom post type and I wrote this    $query = new WP_Query(array(        'post_type' => 'x-video',        'post_status' => 'publish',        'posts_per_page' => -1    ));    /loop code/    pagenavi();   This query is retrieving all published posts at once and I am looping through the results and displaying one page.  What I need is, I want it to be paginated with 12 posts per page. How can I do that?  If I put 'posts_per_page' => 5 then it is showing only 5 posts but not pagination


Restoring WhatsApp backup from iCloud Drive

I have a problem with restoring iCloud WhatsApp backup on my new iPhone. Some time ago I created WhatsApp iCloud backup and then sold the phone. I've bought a new iPhone, inserted the same sim-card, signed in the same Apple ID account. When I open WhatsApp app it tries to find my iCloud backup and always says that no backup found. I have read that question:  and have found all .icloud files on my Macbook. But I don't understand how I can import them on new phone. Moreover, I've read that: . I've already checked that my new iPhone has the same name as the previous one. PS: The first thing I did is writing to WhatsApp support. They have answers like "we cant help you with data restoring".


If “I woke up at 10” is okay, what about “I slept at 10”?

When did you wake up?      I woke up at 10.   But then if I say, “When did you sleep?”     I slept at 10. – seems difficult to digest!   That's because sleep is a process that includes duration.     I slept for 10 hours. – this way, it's digestible!   But when I mention the point of time, is it okay?   Strange thing is, if I'm describing my habit/routine, it's perfectly fine..     I sleep at/by 10     I request not to take this question 'logically'. It's about English. Nobody is perfect in timing. Please don't argue that you cannot have 'perfect time' of sleeping because you don't know when you slept. I'm talking about the sentence structure and not precise timings.   By the way, “I slept at 10” is very common in India.


Room-specific welcome message for new users

Lots of the bigger channels have some kind of rules, stuff people are supposed to read before posting or requesting access, etc.  In the topic it clutters valuable space that can be used for more useful things (regulars usually don't need a link about when to request access etc. there). When a bot pings newly joining user with the message it's even more annoying since it gets pretty spammy for everyone in there.  So my suggestion is to allow room owners to define a welcome message for their room. It could contain markdown (either true markdown or like normal chat messages) and would be shown to a user who has never talked in the room and hasn't been in the room ever or at least for some time (1 month maybe).  Possibly users should be required to click a "confirm" button to be able to talk - otherwise they'll most likely just ignore it without even bothering to read it (yes, I'm talking to you, help vampires)


Android NullPointerException despite it is not null?

java.lang.RuntimeException: Unable to start activity   ComponentInfo{com.exampledinLoginActivity}:   java.lang.NullPointerException   protected void onCreate(Bundle savedInstanceState) {         Log.d(TAG, "login activity OnCreate************");          super.onCreate(savedInstanceState);         dbHandler = new DatabaseHandler(this);           wasDbExisted = dbHandler.ifDatabaseExists();         Log.d(TAG, "login activity wasdbexister="+wasDbExisted);         if (wasDbExisted &&//if db exists, this becomes true to send to mainactivity. mainactivity needs to know if db existed or not                  !dbHandler.isLoginRemember().equals(null)) {//isloginremember returns string, username if loginremember checked, if not only returns null Intent i = new Intent(LoginActivity.this, MainActivity.class);             i.putExtra("username", dbHandler.isLoginRemember());             i.putExtra("wasDbExisted", wasDbExisted);              startActivity(i);             finish();         }   This is first activity of my applicaiton. Login activity. It checks if db exists, if db exists and in database, loginremember is true, it goes to mainactivirt directlry without setcontent (this worked).  But if db doesnot exist , it setscontent and gets username password. or if loginremember false.  Caused by: java.lang.NullPointerException                                                                                at com.example.caneraydin.androidwithlogin.LoginActivity.onCreate(LoginActivity.java:167)  error is that for that line:   if (wasDbExisted &&   but logs say  login activity wasdbexister=true   to sum up  Log.d(TAG, "login activity wasdbexister="+wasDbExisted);//log output is true for this         if (wasDbExisted &&//it gives nullexception for this   this is my manifest  <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"     package="com.example.caneraydin.androidwithlogin">      <uses-permission android:name="android.permission.INTERNET" />     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>     <uses-permission android:name="android.permission.READ_PHONE_STATE"></uses-permission>     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />      <application         android:allowBackup="true"         android:icon="@mipmap/ic_launcher"         android:label="@string/app_name"         android:supportsRtl="true"         android:theme="@android:style/Theme.Black.NoTitleBar.Fullscreen">         <activity android:name=".LoginActivity"             android:screenOrientation="landscape" >             <intent-filter>                 <action android:name="android.intent.action.MAIN" />                   <category android:name="android.intent.category.LAUNCHER" />             </intent-filter>         </activity>          <activity android:name=".MainActivity"             android:screenOrientation="landscape">         </activity>       </application>  </manifest>   this is dbexists method of dbhandler class  public boolean ifDatabaseExists() {          Log.d(TAG,"dbhandlerifdbexists");          SQLiteDatabase db = this.getWritableDatabase();          Cursor mCursor = db.rawQuery("SELECT * FROM " + TABLE_OBJECT, null);//it is looking for object tble to check if db is null or not         Boolean dbExists;      if(mCursor.moveToFirst())     {         Log.d(TAG,"dbhandlerifdbexists true");         dbExists = true;     }      else     {         Log.d(TAG,"dbhandlerifdbexists false");         dbExists = false;     }          return dbExists; }   in my activity, the code is like that  if (wasDbExisted &&                 !dbHandler.isLoginRemember().equals(null)) {   it shows first line.


Posted a bounty, now my reputation is too low to comment on the bounty question

My reputation was 89, then I posted a 50pt bounty on a question.  Now with a reputation of 39, I cannot comment on that same question.    I believe further comments may help anyone trying to answer that question. Shouldn't I at least be able to comment on my open bounties?


I need some help with the format of a paper on overleaf.com

I have been using a template for homework assignments in overleaf.com. It is working well, but unfortunately, there are some ugly checkboxes in every problem line. How do I make this go away ?  Here is the code :   \documentclass[10pt]{article}  \usepackage[margin=1in]{geometry}  \usepackage{amsmath,amsthm,amssymb, graphicx, multicol, array}  \newcommand{\N}{\mathbb{N}} \newcommand{\Z}{\mathbb{Z}}  \newenvironment{problem}[2][Problem]{\begin{trivlist} \item[\hskip \labelsep {\bfseries #1}\hskip \labelsep {\bfseries #2.}]}       {\end{trivlist}}  \begin{document}  \title{Pigeonhole Principle} \author{Name} \maketitle  \begin{problem}{1} Let $a_1, a_2, \dots a_n$ be a sequence of integers. Prove that there is    always a subsequence $a_i, a_{i+1}, a_{i+2}, \dots a_{i+k}$, such that  $a_i +   a_{i+1} + \dots a_{i+k}$ is a multiple of $n$. \end{problem}  \begin{proof} Write a solution here \end{proof}  \begin{problem}{2} If there are $25$ points, such that among any three of them there are two     who's distance is less than $1$. Prove that there is always a circle of radius    $1$ which contains $13$ points. \end{problem}  \begin{proof} Write a solution here \end{proof}  \end{document}   The problem is at the end of the solution line there is a box, which I want to remove.


How do I check if I'm running on Windows in Python?

I found the platform module but it says it returns 'Windows' and it's returning 'Microsoft' on my machine. I notice in another thread here on stackoverflow it returns 'Vista' sometimes.  So, the question is, how do implemement?  if isWindows():   ...   In a forward compatible way? If I have to check for things like 'Vista' then it will break when the next version of windows comes out.    Note: The answers claiming this is a duplicate question do not actually answer the question isWindows. They answer the question "what platform". Since many flavors of windows exist none of them comprehensively describe how to get an answer of isWindows.


I encountered an inequality that I have no idea how to prove.     $ |\mathrm{Tr}(A^*B)| \leq ||A|| \cdot ||B||_1 $, where $A^*$ is the adjoint of $A$, and $||A||$ denotes the spectral (or operator) norm of $A$, and $||B||_1$ denotes the trace norm of $B$.   Maybe the first step we can do is to assume w.l.o.g. B is diagonal. But what to do then?


$\sum_{n=1}^{\infty} \frac{n^2}{ n!}$ equals

$ \sum_{n=1}^{\infty} \frac{n^2}{ n!} $ equals  I'm not able to convert in any standard series? Any hints?


Insert Unicode characters via the keyboard in Windows 10 on a laptop without a numeric keypad

I have already read this answer . However I have tried that on Windows 10 and it didn't seem to change anything. Considering that the solution was from back in 2009, perhaps there is something else that needs to be done in order to get it to work. Any pointers would be helpful.   EDIT:  It seems that for this to work, you have to type the "+" key on the numeric keypad. What about those on a laptop and no numeric keypad?


\documentclass[12pt]{article}     \usepackage{fixltx2e,graphicx,amsmath,mathptmx,tikz,tkz-euclide,pgfplots} %for math     \usetkzobj{all}     \usetikzlibrary{calc}     \begin{document}     This is a square     \begin{tikzpicture}[thick]     \coordinate (L) at (0,0);     \coordinate (M) at (2,0);     \coordinate (N) at (2,2);     \coordinate (P) at (0,2);     \draw      (L) node[below left] {\footnotesize{$L$}} --     (M) node[below right] {\footnotesize{$M$}} --     (N) node[above right] {\footnotesize{$N$}} --     (P) node[above left] {\footnotesize{$P$}} --      cycle;     \tkzLabelSegment[below=2pt](L,M){\footnotesize{$4$cm}}     \end{tikzpicture}     Find its area.     \end{document}   Is there any way to make the text inline with the square?


I have an array of bytes that I would like to store as a string.  I can do this as follows:  byte[] array = new byte[] { 0x01, 0x02, 0x03, 0x04 }; string s = System.BitConverter.ToString(array);  // Result: s = "01-02-03-04"   So far so good.  Does anyone know how I get this back to an array?  There is no overload of BitConverter.GetBytes() that takes a string, and it seems like a nasty workaround to break the string into an array of strings and then convert each of them.  The array in question may be of variable length, probably about 20 bytes.


I noticed that in my , the image’s src attribute and the link’s href attribute use HTTP.  It would be much better if the URLs used the HTTPS scheme instead of HTTP. Doing so, would avoid warning about unsafe mixed content when an HTTPS website references insecure (HTTP) resources. As security becomes more important, many sites are moving to using only HTTPS.  It’s also better to link directly to the secure/authenticated version (HTTPS) of the Stack Exchange family of sites. See  for more details.  Obviously, users can change the URL scheme themselves but it would be better to have HTTPS as the default. This would be a small way for Stack Exchange to make the Internet safer and to help normalise the use of HTTPS over HTTP.


Is there a before/after edit view in OS X Photos' Editing view?

I've used photo editing apps before that show a before/after split view, so you can see the original image and the edited image either side by side or overlaid. Like this:    Is there a similar editing view in OS X Photos?


Where is this place "several houses on the rocky coast and rocky island with natural arch"?    If you think that I can check location on windows lock screen () look at this and tell me how:


How do I reference photographs with a separate numbering system to figures in latex?

I am writing a book, and would like to be able to have the photographs labelled with an independent numbering system to my figures.  In the text I would refer to, for example, figure X and separately to photograph X, so I want them to have different numbering systems, just as equations and figures do.  Is it possible to have a different \begin{figure} environment so that the numbering can be separated?


A  is an informal term for:     A woman who associates with or marries a man chiefly for material gain   What would the gold digger's man be called? A mark? A sugar daddy?    Edit: I'm editing after my sugar daddy term has been reposted a couple of times, strangely with great success. I'd like a term for a man being targeted by the gold digger. So obviously as I listed sugar daddy in the question I felt that it was unsatisfactory; for example it works poorly here:     He's her sugar daddy.   While this is very accurate for a gold digger's man. You cannot take from this that he's being targeted, it even sounds like he's doing the targeting. This is closer:     He's her mark.   It's clear that he is being targeted. But unless the gold digger is also an assassin it seems a bit unclear what he's being targeted for.


Gravity anomaly in Lacnov, Slovakia: Gravity ashamed

(Sorry: above links in Slovak.)   Can someone explain this to me? Is it a hoax?  (In case of link rot try  or  Youtube search.)


Why does my Saved image after render has black background instead of transparent, but I already set the Film to Transparent?

Hello, I need help with this problem. When I render my image the background is transparent, but when I save it, it has a black background. How can I save it without the black background?


Force Internet Explorer 10 to open in non-compatibility view

Is there any way to force IE10 to open all sites in non-compatibility view? The only way I can do it is by pressing F12 and changing the mode but I have to do it every time I open a new tab. The list for websites to open in compatibility view is empty.  Edit:  The compatibility view settings are like this:     Websites added is empty  Display all is uncheck  Display intranet is uncheck  Download list is uncheck


I'm trying to send an email to several recipients when a new row is inserted into a table. The list of recipients varies.  I would like to be able to set this list using a select statement.  I also have installed Navicat which allows me to send email notifications but only to a predetermined set of people.  Thanks.


Keyboard Shortcuts Not Working When Not in English in 20.04

I've recently updated to Ubuntu 20.04. When English is not the chosen language all shortcuts don't work (such as Ctrl + C, Ctrl + A, etc). It was working fine in the previous versions. What happened and What can I do to fix it?


Polynomial maximization: If $x^4+ax^3+3x^2+bx+1 \ge 0$, find the maximum value of $a^2+b^2$

If $x^4+ax^3+3x^2+bx+1 \ge 0$ for all real $x$ where $a,b \in R$. Find the maximum value of $(a^2+b^2)$.                                                                        I tried setting up inequalities in $a$ and $b$ but in the end had a hideous two variable expression whose maxima I had to calculate using Partial Derivatives. There must be a better way of doing it. Thanks!


Why is $1$ not considered a prime number?  Or, why is the definition of prime numbers given for integers greater than $1$?


Why php5-fpm is depending of a "sury.org" version of php5-common?

I try to install php5-fpm package but I have this information:   The following packages have unmet dependencies:   php5-fpm : Depends: php5-common (= 5.5.7+dfsg-1+sury.org~quantal+1) but 5.3.10-1ubuntu3 is to be installed  E: Unable to correct problems, you have held broken packages.   Here is full terminal output:  root@myserv /home/pw # sudo apt-get install php5-common Reading package lists... Done Building dependency tree        Reading state information... Done php5-common is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 43 not upgraded.   and:  root@myserv /home/pw # sudo apt-get install php5-fpm --fix-missing --fix-broken Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  php5-fpm : Depends: php5-common (= 5.5.7+dfsg-1+sury.org~quantal+1) but 5.3.10-1ubuntu3 is to be installed E: Unable to correct problems, you have held broken packages.   How to fix it?


Can anyone suggest me whats the difference between Line 1 and LINE 2.Which is the preferred way?If we can create an object ,then why do we use static block? what is the order of execution of static members in a class?  class Foo {  static {     // bar = new Bar();     System.out.println("IN Block");//LINE 1 } public static Bar bar = new Bar();//LINE 2  public void doStuff() {     System.out.println("I am in Foo");  } }   Thanks


I want to make a USB cell phone charger. I know USB operates in 5 volts which means i need to drop down voltage if i have battery potential greater than 5 Volts. I have 12 volts sealed lead acid battery (SLA) of capacity 9AH. I need to drop down the voltage for which i am using LM2596 buck regulator ( Switching power supply) and it can deliver 3 amperes of current. But my cell phone charger(came with the product) is rated for 2A. So i was wondering how can i limit the current so that it doesnot blow my Cell phone. Thanks


Increase persistent file size to greater than 4 gigabytes

My USB's 16 GB, but I only get to use 4 GB in persistence file. Any way to increase it?


Is it possible to lookup people picker type field

Is it possible to lookup a people picker type field from a list. I have tried OOTB as well. But I couldn't do it through OOTB even. I need something like as following: Here "Person" is a people picker type field.  <Field Name="Person" ID="{d74b3913-2c09-4e17-ad28-3ec11ac4be31}" DisplayName="Person" Type="Lookup" List="Lists/Persons" ShowField="Person" />


Say I do the following:  cd ~ pushd . cd /bin/ pushd . dirs "/bin/ ~/ cd ~/Downloads/ pushd . dirs ~/Downloads /bin/ ~"   How would I popd back to something a while ago, say from downloads to the home directory~?


Twin Paradox in case of two twins that don't meet

If there are two twins. such that one of them goes on a space voyage maintaining a constant velocity, and that one never returns to earth, and the twins decide to never meet but send information about their age to each other by some light pulse or any other method.  If then one knows that he is younger, won't he know he is the one travelling thus violating the postulate of relativity that all inertial frames are equal w.r.t. all phenomena and that one can never know if he is moving with a constant velocity.


Last session, I was running, as DM, the adventure from the Starter Set(Lost Mine of Phandelver) and one of the pregenerated characters is a Lightfoot Halfing Rogue with the Naturally Stealthy ability, which a player was using to hide during combat.     Naturally Stealthy. You can attempt to hide even when you are obscured only by a creature that is at least one size larger than you.(PHB p.28)   My problem is that I am confused as to what hiding means. Are you considered hidden only when you're stationary and/or behind some kind of cover or does it mean that even if you move, you're "lurking in the shadows" so you can still have the Unseen Attackers advantage?


Although I'm doubtful, I'm curious as to whether it's possible to extract primitive-type template parameters from an existing type, perhaps using RTTI.  For example:  typedef std::bitset<16> WordSet;   Would it be possible to extract the number 16 in the above code without hard-coding it elsewhere? Compiler specific implementations are welcome, though I'm particularly interested in g++.


Difference Between Pointer(*) And Reference(&)

I use Reference(&) here,but the a didn't change.Why? While i use Pointer(*) the value have changed.  int all=0;  void call_from_thread(int & a)   {    a = 5; }  int main()  {     thread s = thread(call_from_thread, all);     s.join();     return 0; }   Another program,in this case, i also use Reference(&),but the value have changed. Why the value a in thread didn't change?  void Func3(int &x) {     x = x + 10; }  int main() {      int n = 0;     Func3(n);     cout << “n = ” << n << endl; // n = 10 }


Why aren't my guide and other dead NPCs respawning in Terraria?

I am currently in hard mode and during a blood moon, several of my NPCs including my guide and my healer died. it's been several in game "days" now and they have yet to respawn. Is there a way to check why they aren't respawning?   Is there a list of reasons for the NPCs to not respawn?   Edit in reponse to lunbok's answer:  1. They don't have appropriate housing - There is an in-game housing query function (changes your cursor into a ?) that lets you click on your house to see if it is still a suitable house and I clicked in every room in my house and they are all listed as "This housing is suitable" or "This housing is already occupied".  2. Their spawn conditions aren't met anymore. - This doesn't explain why my guide isn't respawning since they don't need a condition to respawn (other than having a suitable housing which the point above already prove isn't the problem).  3. There's a goblin invasion going on. - Do the invasions last that long? It has been about two reals days and a lot more in-game "days" now. As far as I can tell there shouldn't be an invasion going on.  4. It could be because you built your house in a part of the world that is now corrupted


Why does this equation have 6 solutions in $\Bbb{C}$,      $$|z| = z^5$$


Not being a first author diminishes the contribution of co-authors?

If a group of students (say, 3 students), produces a work which has been accepted to a reputable conference. All of them contributed equally to the project,from implementation to writing and proof reading of the paper.  How should one decide who should be the first author. Even if the names are listed in alphabetical order, so by not being the first author, does it affect the prospects for the other two in any means ?  My field of research is computer science.  (This question has been partly inspired by the  flurry of questions on ASE, regarding the importance of being the first author)


Proving for all integer $n \ge 2$, $\sqrt n < \frac{1}{\sqrt 1} + \frac{1}{\sqrt 2}+\frac{1}{\sqrt 3}+\cdots+\frac{1}{\sqrt n}$

Prove the following statement by mathematical induction: For all integer $n \ge 2$, $$\sqrt n < \frac{1}{\sqrt 1} + \frac{1}{\sqrt 2}+\frac{1}{\sqrt 3}+\cdots+\frac{1}{\sqrt n}$$  My attempt: Let the given statement be $p(n)$ .  1.\begin{align*} \frac{1}{\sqrt 1} + \frac{1}{\sqrt 2} & =\frac{\sqrt 2 +1}{\sqrt 2} \\  2 &< \sqrt 2 +1 \\ \sqrt 2 &< \frac{\sqrt 2 +1}{\sqrt 2}=\frac{1}{\sqrt 1} + \frac{1}{\sqrt 2}  \end{align*}  Hence, $p(2)$ is true.  2.For an arbitrary integer $k \ge 2$, suppose $p(k)$ is true. That is, $$\sqrt k < \frac{1}{\sqrt 1} + \frac{1}{\sqrt 2}+\frac{1}{\sqrt 3}+\cdots+\frac{1}{\sqrt k}$$  Then we must show that $p(k+1)$ is true. We're going to show that $$\sqrt {k+1} < \frac{1}{\sqrt 1} + \frac{1}{\sqrt 2}+\frac{1}{\sqrt 3}+\cdots+\frac{1}{\sqrt k}+\frac{1}{\sqrt {k+1}}$$  I'm stuck on this step. I can't develop it further. How can I complete this proof?


Oppossing Laser Beams Cause One Beam to Disappear

I posted a video early where I asked the question about opposing laser beams appearing to turn one laser off. Further experiments, however, have demonstrated that it is interference at play not that one laser quits working. Yet, two separate lasers do not create the destructive interference to the extent that my experiment shows. The experiment is two lasers beams facing directly into each other with a 45 degree beam splitter between them. One beam disappears. What happening? I posted two videos to show what happens


Font issue in math mode in Beamer metropolis theme

I'm learning to use the beautiful Metropolis theme, but I have a long-standing problem with the fonts in math mode. As you can see from the image, the font of the elementary functions is poorly displayed. I'm compiling with XeLaTex.  This is my code \documentclass[aspectratio=169]{beamer}         \usetheme[progressbar=foot,numbering=none]{metropolis}         \usepackage[italian]{babel}         \usepackage[utf8]{inputenc}         \usepackage{centernot}         \usepackage{enumerate}         \usepackage{array}         \usepackage{fontspec}         \usepackage{semantic}        \begin{document}     \begin{frame}         \begin{itemize}[<+->]             \item $a_n = |n|$ (valore assoluto)             \item $a_n = n^2$ (potenza ad esponente pari)             \item $a_n = n^3$ (potenza ad esponente dispari)             \item $a_n = \frac{1}{n^2}$ (reciproco di potenza pari)             \item $a_n = \frac{1}{n^3}$ (reciproco di potenza pari)             \item $a_n = \sqrt[2]{n}$ (radice di indice pari)             \item $a_n = \sqrt[3]{n}$ (radice di indice dispari)             \item $a_n = \log_2 n$ (logaritmo con base maggiore di 1)             \item $a_n = \log_{\frac{1}{3}} n$ (logaritmo con base tra 0 e 1)             \item $a_n = 2^n$ (esponenziale ad esponente maggiore di 1)             \item $a_n = \left( \frac{1}{3} \right)^n$ (esponenziale ad esponente tra 0 e 1)             \item $a_n = \sin n $ (seno)             \item $a_n = \cos n $ (coseno)               \item $a_n = \tan n $ (tangente)             \item $a_n = \arcsin n $ (arcoseno) \end{itemize}     \end{frame}     \end{document}  Thank you all.


I'm curious is there any faster way to reduce the size of jpeg files. My jpeg files are about 6MB per file. I open each file in a simple Paint program and press Ctrl+S to resave the image. File resaved with  let's say 1.3Mb. The quality is worse, but it is still OK to view the image. I do it for each file that is over 2Mb.  Is there any way to do it for over a 1,000 jpeg image files much faster?  P.S. Windows XP or 7 is the OS I'm looking for a solution for.


GNOME System Monitor is showing tons of file systems (18.04.3)

I installed Ubuntu on 2 PCs the past few days. On one it was Kubuntu 18.04.3 -> Install ubuntu-desktop and I get the monitor showing file systems nicely, like this:    The second computer, causing me this issue, was a fresh install of Ubuntu 18.04.3 yesterday and the monitor shows file systems with a crazy amount like this:    The only setting I see that might pertain to this is 'Show all file systems', which is unchecked:    Searching here and Googling haven't brought me anyone with the same issue.


I've been trying to install any version of Ubuntu on an old PC I have (specs shortly). Every time I try to install any version (I've tried 16.04.6 32bit & 64bit, 18.04 & 20.04) I receive the same error: hdaudio hdaudioC1D0: no AFG or MFG node found There are several lines of this error from "C1D0" to "C1D7" that appear when I try to install, followed by snd_hda_intel 0000:01:00.1 no codecs initialized. These errors also appear when I try to run Ubuntu from the USB I made with Rufus (Also tried Universal USB Installer). After the errors, the screen glitches and the PC seems to try and reboot and posts every 30 seconds or so. The hardware: AMD FX-4100 Gigabyte GA-970A-D3 Rev 1.3 with F12 BIOS GPU is a GTX580 I have reseated all cable connections on the motherboard, and also changed GPU's as I thought that may have been the problem due to the . I have also tested the USB on my Windows 10 desktop, and it works fine. I have also used multiple USB's and USB ports. Any help will be greatly appreciated. Edit: I have had success installing Manjaro, so I can at least confirm it's not a kernel issue.


Example where $f\circ g$ is bijective, but neither $f$ nor $g$ is bijective

Can anyone come up with an explicit example of two functions $f$ and $g$ such that: $f\circ g$ is bijective, but neither $f$ nor $g$ is bijective?  I tried the following: $$f:\mathbb{R}\rightarrow \mathbb{R^{+}} $$ $$f(x)=x^{2}$$  and  $$g:\mathbb{R^{+}}\rightarrow \mathbb{R}$$ $$g(x)=\sqrt{x}$$  $f$ is not injective, and $g$ is not surjective, but $f\circ g$ is bijective  Any other examples?


How do you select elements based on their style?

Using jQuery, how would you find elements which have a particular style (eg: float: left), regardless of whether it's an inline style or one defined in a CSS file?


How do I safely delete old kernel versions in CentOS 7?

I might be encountering odd symptoms resulting from competing kernels in CentOS 7.  So how do I safely delete the old kernels?  And how do I know which kernel is the newest one?    Below is the terminal output I get at the moment when researching this on the server in question.  Note that I tried package-cleanup but it leaves the same 2 kernels:     say that the output of the following two commands should match, but you can see that they do not match, even after a reboot:    [root@localhost ~]# rpm -qa kernel |sort -V |tail -n 1 kernel-3.10.0-229.el7.x86_64 [root@localhost ~]# uname -r 3.10.0-229.14.1.el7.x86_64   The remaining commands confirm that there are two kernels, and illustrate attempts to delete the old one.    [root@localhost ~]# cd /usr/src/kernels [root@localhost kernels]# ls -al total 16 drwxr-xr-x.  4 root root 4096 Oct  2 12:55 . drwxr-xr-x.  4 root root 4096 Oct  2 13:15 .. drwxr-xr-x. 22 root root 4096 Oct  2 12:55 3.10.0-229.14.1.el7.x86_64 drwxr-xr-x. 22 root root 4096 Oct  2 12:35 3.10.0-229.el7.x86_64 [root@localhost kernels]# rpm -q kernel kernel-3.10.0-229.el7.x86_64 kernel-3.10.0-229.14.1.el7.x86_64 [root@localhost kernels]# package-cleanup --oldkernels=1 Loaded plugins: fastestmirror Usage:      package-cleanup: helps find problems in the rpmdb of system and correct them      usage: package-cleanup --problems or --leaves or --orphans or --oldkernels Command line error: --oldkernels option does not take a value [root@localhost kernels]# package-cleanup --oldkernels Loaded plugins: fastestmirror No old kernels to remove [root@localhost kernels]# rpm -q kernel kernel-3.10.0-229.el7.x86_64 kernel-3.10.0-229.14.1.el7.x86_64 [root@localhost kernels]#    I also opened up /etc/yum.conf and set installonly_limit=1, but this resulted in an error from a subsequent yum update command saying that 1 is outside the range of acceptable values for installonly_limit.    I assume that 3.10.0-229.14.1.el7.x86_64 is the newest, but how can I know this?  Also, the boot options seem to offer multiple kernels to choose from.  And the opportunities for confusion get worse when the system auto-boots from the first kernel on the list of options.    Can someone please explain how this works, and in specific, how to safely delete old kernels so that kernel version can be eliminated as a possible cause of odd symptoms?  I want to make sure that the most recent kernel is the only kernel that can ever run, no matter how the system is restarted.


Is "/bin/[.exe" a legitimate file? [Cygwin, Windows 10]

I can not find anything about this, is it a known file? I am using a CYGWIN based terminal on windows 10  Here are their locations and the commands I used.  $ find -name [* ./bin/[.exe ./usr/bin/[.exe    $ ls -l -a -r /* | grep [-.*\>] ...all other files that match this... -rwxr-xr-x 1 X 197121   67134 Nov  6 14:22 [.exe drwxr-xr-x 1 X 197121       0 Apr  2 18:15 .. drwxr-xr-x 1 X 197121       0 Jan 26 03:20 .   I would like more information on this file and whether or not I can remove it.


Use the unique prime factorization property of $\mathbb{Z}$ (fundamental theorem of arithmetic) and the Schroeder-Bernstein theorem to show that  $$| \mathbb{N} | = | \mathbb{N} \times \mathbb{N} |.$$  Anyone knows how to start this question?  I know that Schröder–Bernstein theorem, states that, if there exist injective functions f : A → B and g : B → A between the sets A and B, then there exists a bijective function h : A → B.  But then I don't know how to apply it to this question and write a detailed approach to it. Help would be appreciated.


Show that Symmetric Group $S3$ and $GL(n,\mathbb F_2)$ is an isomorphism.  $\mathbb F_2$ has $2$ elements - $0,1$.  In $GL(n,\mathbb F_2)$ there are $2$ choices for each entry so $8$ possible matrices in total.  But the symmetric group $3$ has order $6$. The cycles are:  $[],[1,2],[1,3],[2,3][1,2,3],[1,3,2]$  How can I show that they are isomorphic?


Relationship between strict stationarity and 2nd order stationarity

I've been reading my GARCH class notes and I found some discussions about stationarity.   "In Finance, stationarity of order 2 is often considered as more restrictive than the strict stationarity, because the financial returns often display distributions with fat tails (and thus only low-order moments are likely to exist)."  I don't see why stationarity of order 2 is more restrictive than strict stationarity ?? I mean strict stationarity implies the joint distribution of any moments (including moments of order two) of any degree within the process is never dependent on time.


Overnight at Schiphol airport or hotel needed?

I will go from Belgium (Brussels Midi Railway Station) to Netherlands (Schiphol airport) so I am supposed to arrive there on Saturday at 11:24pm and then wait like 10h for my next flight which takes place on Sunday at 12:30pm but I am not allowed to do the check-in until 9:30am.  So, I'd like to know if I would need to book a hotel or (if not) how "rude" is to sleep at Schiphol airport. For sure this is different from airport to airport and I was thinking to probably follow  but I am not sure.  However, if booking a hotel is needed, I thought about getting a room at  (inside the airport) but I am not sure if I will be allowed to get inside since I won't be in transit/boarding area until 9:30am - Is that possible?   On the other hand, if that's not the right hotel, which one could fit better from the following  of hotels available at Schiphol for this scenario?


throwing a dice repeatedly so that each side appear once.

Pratt is given a fair die. He repeatedly  throw the die until he get at least each number (1 to 6).   Define the random variable $X$ to be the total number of trials that  pratt throws the die. or  How many times he has to throw a die so that each side of the die appears at least once.  Determine the expected value $E(X)$.


Canon ixus 85is achieve 50mm focal length

Hi can please anyone help me. How can i achieve a 50mm focal length on my camera? On the outside of the lens there is written 6.2-18.6mm  thanks a lot


How can I solve this recursion question, I am really stuck.

I am doing a couple of exercise questions, How do I show that if we let  $n \geq 1$ be an integer, and if we consider $n$ people $P_1$,$P_2$,...,$P_n$. If we let $A_n$ be the number of ways these $n$ people can be divided into groups, such that each group consist of either one or two people.  How do we determine $A_{1}$, $A_{2}$, and , $A_{3}$ and how do we prove that for each integer $n\geq 3$,  $A_{n}$ = $A_{n-1}$ + $({n-1})$ $\cdot$ $A_{n-2}$


If-statement checking for filename correctness (appending ".txt") not working

So I want to accept a file name from the user. I then want to check if the last four characters of the string are ".txt". If they aren't, append ".txt" to the end of the user inputted string. If they are, skip. Simple.  But it's not working - when I enter "exampledata.txt" it still adds ".txt" and throws a FileNotFoundException - and I can't figure out why. I've taken the same calculation and printed it out/verified in debugger; my method call to substring is correct.   Relevant code:  import java.util.*;  import java.io.*;  public class MappingApp {     public static void main(String[] args) {         Scanner sc = new Scanner(System.in);          String userInput;         System.out.print("Enter file to read from: ");         userInput = sc.nextLine();          if ( (userInput.substring(userInput.length()-4, userInput.length())) != ".txt" ) {             userInput += ".txt";         }          try {             File f = new File(userInput);             BufferedReader br = new BufferedReader(new FileReader(f));         }         catch (FileNotFoundException e) {             System.err.println(e);         }     }  }


How to retry the callout on http request timed out in rest apex callouts?

Below is the code. Can anyone tell how to implement retry logic when the 2 minutes http request get timed out. public static void sendOptyInfo(Set <Id> oppIdSet) {     try{         for (Opportunity opp: [SELECT id ,StageName, Account.Name  from Opportunity where id in: oppIdSet]){                          String jsonBody = JSON.serialize(new Wrapper(opp));             HttpRequest request = new HttpRequest();             HttpResponse response = new HttpResponse();                          Http http = new Http();                          Api_Request__c apiReq = new Api_Request__c();             apiReq.Opportunity__c = opp.id;             apiReq.Stage_Name__c = opp.StageName;             apiReq.Account_Name__c = opp.Account.Name;                          insert apiReq;                          request.setEndpoint('');             request.setHeader('Content-Type','application/json');              request.setMethod('GET');             request.setBody(jsonBody);             request.setTimeout(120000);             system.debug('opp json' +jsonBody);                          response = http.send(request);             if (response.getStatusCode() == 200) {                 System.debug('Response-' + response);                 Object results = (Object) JSON.deserializeUntyped(response.getBody());                              }         }              }     catch(System.CalloutException e){         System.debug('Error-' + e.getMessage());        } }


If characteristic function is $L^2$ does it mean that the distribution is absolutely continuos?

Suppose, we have a characteristic function $\phi(t)$.   Suppose that  \begin{align} \int_{-\infty}^\infty |\phi(t)|^2 dt <\infty \end{align}  Does this mean the corresponding probability distribution is absolutely continuous?  I found that if the following condition  holds \begin{align}  \lim _{T \to \infty} \frac{1}{2T}\int_{-T}^T |\phi(t)|^2 dt=0 \end{align} then the distribution is contionous.   However, I think they mean continuous and I am not sure if this implies existence of density.


Errors:  Attempt to invoke virtual method 'android.view.View android.widget.ImageView.findViewById(int)' on a null object reference   or  java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageView.setImageDrawable(android.graphics.drawable.Drawable)'   SecondLayout.xml:  <ImageView     android:id="@+id/cafe"     android:layout_width="100dp"     android:layout_height="90dp"     android:layout_alignParentEnd="true"     android:layout_alignParentRight="true"     android:layout_alignParentTop="true"     android:layout_gravity="right"     android:src="@drawable/cafe" />  <ImageView     android:id="@+id/baron"     android:layout_width="100dp"     android:layout_height="90dp"     android:layout_alignParentEnd="true"     android:layout_alignParentRight="true"     android:layout_alignParentTop="true"     android:layout_gravity="right"     android:src="@drawable/bar" />   The first class has OneLayout.xml  ExampleBottomSheetDialog.class has SecondLayout.xml  In the first class, when you click on the marker, ExampleBottomSheetDialog.class is activated:  public boolean onMarkerClick(final Marker marker) {      ExampleBottomSheetDialog bottomSheet = new ExampleBottomSheetDialog();     bottomSheet.show(getSupportFragmentManager(), "exampleBottomSheet");      // Image replacement     if (...) {         ImageView img= (ImageView) findViewById(R.id.cafe);         img.setImageResource(R.drawable.bar);     }   How to resolve issue with null object?


How do you use strikethrough on Stack Exchange?

I am trying to use strikethrough on . (Now updated with working strikethrough) I have tried the following:   ~~Double tildes~~ ~Single tildes~ [strike]Strike[/strike] [del]Del[/del] [s]S[/s]   None of these work. I know there is a way because I've seen it before on Stack Exchange.


What are the names for Magic's different colour combinations?

For example, Esper refers to decks made up of White, Blue and Black cards.  What are the names of the other colour combinations? In particular, how do we refer to a Red-White-Black deck?


Why does Type variable; does not call the default ctor?

Let's assume the following class Foo.  struct Foo {   int i;   bool j; };   Why do I get different results from the following lines?  int main(void) {     //I thought the default constructor would be called     Foo foo1;     cout << foo1.i << " : " << foo1.j << endl; // " 4196352 : 0 " --> ctor not called?      //if calling the default constructor explicitly     foo1 = Foo();      cout << foo1.i << " : " << foo1.j << endl; // " 0 : 0" --> ctor called. }    Shouldn't the default ctor be implicitly called?  According to :     If no user-declared constructors of any kind are provided for a class type (struct, class, or union), the compiler will always declare a default constructor as an inline public member of its class.


How to close mongodb idle connection(active: false)?

I have an application running on node and using the mongodb library to establish connection and closing it. But the problem is, from the mongo serverStatus() command i can see that there is still 2k+ current connections still available.  > db.serverStatus().connections { "current" : 2993, "available" : 835867, "totalCreated" : 220841 }   and most of it are having the active: false status.  My questions is, is there a way for me to force close these idle connections which after some time will affect my application with an timeout error.  I tried using the killOp() command but these only works if there is still opid value listed in these idle connections.  Appreciate some feedback on how can handle this kind of situations.


How to decrease the motor Speed without losing the maximum Torque

I am using MDS40A motor driver() to drive a power window motor (12V, brushed motor) similar to the one at (). I am using PWM generated by Arduino to control the speed of the motor. As I use lower value of PWM to get slower speed (the current gets reduced as well), the torque of the motor is drastically reduced. I am using Arduino Uno.  What I have understood is that with PWM, the voltage and current are not affected by the duty cycle. Torque depends on available current, while RPM depends on available current or amount of time it is ON. When the motor is ON, it resists load (accelerates) and when it's OFF it does not resist load (gets slowed by load/decelerates), hence RPM can be controlled by amount of time motor is ON, while torque stays at max due to max current at ON period.  I want to decrease the motor speed without losing the maximum torque. Can anyone help me on this? Can it be done with code?


Have there been any anime with actual product placement?

In Steins;Gate, Dr. Pepper is mentioned several times as the "An Intellectual Drink, For The Chosen Ones".    I've seen a lot of other shows that have stores or products with similar names to the real-life brand, so that the producers can avoid copyright issues.     Even though the inclusion of Dr.Pepper wasn't asked for by the Dr.Pepper company, after the release of Steins;Gate the sales in Japan for Dr.Pepper shot up. .   Have there been any anime where a company has paid for their product to be included in the show?


Any time I try to install anything or run apt update, I get this error:  E: The repository 'http://ppa.launchpad.net/armagetronad-dev/ppa/ubuntu bionic Release' does not have a Release file.  N: Updating from such a repository can't be done securely, and is therefore disabled by default.  N: See apt-secure(8) manpage for repository creation and user configuration details.   I'm not skilled enough to figure this out. I've seen that I can try ppa purge but I don't know how.


What does it mean to have a program with too many data connections between functions?

Most likely an incredibly silly question but here goes.  So I am currently reading the C book by Kernighan and Ritchie and I am a bit confused as to what the effect of too many data connections has on the program. Is it strictly to do with the appearance and readability of the code or does it also have an adverse effect on the program ie cause it to be slower.   Below is the paragraph in question.   "If a large number of variables must be shared among functions, external variables are more convenient and efficient than long argument lists. As pointed out in Chapter 1, however, this reasoning should be applied with some caution, for it can have a bad effect on program structure, and lead to programs with too many data connections between functions"


Getting jQuery to recognise .change() in IE

I'm using jQuery to hide and show elements when a radio button group is altered/clicked. It works fine in browsers like Firefox, but in IE 6 and 7, the action only occurs when the user then clicks somewhere else on the page.  To elaborate, when you load the page, everything looks fine. In Firefox, if you click a radio button, one table row is hidden and the other one is shown immediately. However, in IE 6 and 7, you click the radio button and nothing will happen until you click somewhere on the page. Only then does IE redraw the page, hiding and showing the relevant elements.  Here's the jQuery I'm using:  $(document).ready(function () {   $(".hiddenOnLoad").hide();    $("#viewByOrg").change(function () {     $(".visibleOnLoad").show();     $(".hiddenOnLoad").hide();   });    $("#viewByProduct").change(function () {     $(".visibleOnLoad").hide();     $(".hiddenOnLoad").show();   }); });   Here's the part of the XHTML that it affects. The whole page validates as XHTML 1.0 Strict.
   View by:
       <input type="radio" name="viewBy" id="viewByOrg" value="organisation"       checked="checked" />Organisation

       <input type="radio" name="viewBy" id="viewByProduct" value="product" />Product

   Organisation:	        <select name="organisation" id="organisation" multiple="multiple" size="10">       <option value="1">Option 1</option>       <option value="2">Option 2</option>     </select>

   Product:	        <select name="product" id="product" multiple="multiple" size="10">       <option value="1">Option 1</option>       <option value="2">Option 2</option>     </select>
   If anyone has any ideas why this is happening and how to fix it, they would be very much appreciated!


Show $\tan(x)+\tan(y)+\tan(z) = \tan(x) \tan(y) \tan(z)$

I am not able to show that:     If $x+y+z=\pi$, show that $\tan(x) + \tan(y) + \tan(z) = \tan(x) \tan(y) \tan(z)$.


difference between Set = new HashSet and HashSet = new HashSet java

What is the difference between the 2 calls:  Set<Record> instances = new HashSet<Record>();  -  on one hand  HashSet<Record> instances = new HashSet<Record>();  - on other hand


Why does an object with a glossy shader render in black?

When I apply a glossy shader to the material of my text, the text becomes just black. Why?    I have lamp and everything, but the problem persists. The text is red before I add the glossy shader.  I'm using Cycles render.   Thanks!


How to cite a newspaper using Biblatex and Mendeley?

My problem is the following: I use Mendeley to organize my literature. Conveniently, Mendeley is able to generate BibTex files of my groups, which I reference in my LaTeX document. This allows me to easily add a source to my reference manager, go back to my document and basically cite them immediately.  Now, I added a new source which is a newspaper article. Unfortunately, if I choose "Type: Newspaper Article" in Mendeley, the manager creates a Bibtex entry that looks as follows:  @misc{Doe2019,     author = {Doe, Jane},     booktitle = {NewspaperX},     title = {{Hello There!}},     year = {2019} }   This is the Mendeley Default output and it can't be changed!  This does not include the day or month I could enter in the manager, which is... not good. But, okay. More importantly, if I use Biblatex and bibstyle=authoryear, not even the Newspaper name (booktitle) appears in the bibliography. Here a MWE:  \documentclass[a4paper, 12pt]{article}  \usepackage{filecontents}  \begin{filecontents*}{example.bib}     @misc{Doe2019,         author = {Doe, Jane},         booktitle = {NewspaperX},         title = {{Hello There!}},         year = {2019}     } \end{filecontents*} \usepackage[backend=biber,citestyle=authoryear-icomp,bibstyle=authoryear,uniquename=false]{biblatex} \bibliography{example.bib}  \begin{document}     This is my example \parencite[][]{Doe2019}.     \printbibliography \end{document}   Now, here are my questions:   Is it possible to add the newpaper name to the bibliography by changing the LaTeX-file What would be a suitable workaround?  where one includes a ? Abandonding Mendeley because there are more convenient tools out there?   Edit: Using the Type "Journal Article" in Mendeley at least solves the problem to a certain extent.


Newbie question on Macro photography kit

I am newbie here and would like to know what is required to take macro photography. I have seen pictures of flies and insects that are taken very close and they show a lot of details. I would like to take such photographs. I have a D90 and a 18-55 lens that came along with the camera. I have tried to take macro using this lens, by getting close to the object, but could not get the desired results. So please help.  Thanks in advance.


Close votes review does not honor the filter by tag

A related question:   This problem is a little different, because I receive a change in a filter rather than a question from another filter:    Steps to reproduce:   Go to "Review-Close Votes" page Click on a tag that you normally don't answer One question from that tag will be displayed. Decide on it Next question will be from your default filter, not the filter that's displayed.   As you see on a screenshot, I've chosen the [mysql] tag, got one question then bam, filter got changed to [actionscript-3] which I remember being displayed to me ever since I'm determinately crawling on close votes. The displayed filter is [mysql] while it's not in effect.   A workaround is re-applying the filter via "filter" menu.  UPDATE: Once you set the filter via filter tool in close votes page, that filter will apply whenever close vote page will display a new question. So, while the workaround is still valid, the problem is narrowed to the filter request when submitting user decision on closing the given question.


Deleted .dvd file, and "Could not open file for writing."

I just completed my first Blender job. Without thinking, I deleted what I thought was a superfluous .dvd file.   After realizing I rendered my file in black and white instead of RBG, I tried to render my job again but I just get a the warning, "Could not open file for writing." I do have a saved, .blend file. Is it possible to generate another mpeg file from this?


How do I get a variable's value from one script and import it in another script? But the catch is that the script where I am going to get the variable's value has also some commands that I don't want to run:  Let's say this is script1.sh:  variable="Hello" #some command here e.g. yum check-update   And in script2.sh:  echo $var   I've found an approach where one uses the EXPORT command and puts ./script1.sh inside the script2.sh but it runs the other commands.  So, how can I get the variable's value without running the commands inside it? I hope this question is clear. Thanks in advance!


How to log out with spring security basic auth?

Someone can say that this is a duplicate question but I have looked through a lot of answers, tried a bunch of methods but can not understand what I have missed.  I use very basic Spring Security in my REST server. When I first time make a request to my server directly from a browser to localhost:.../getData I am of course asked to authorize.   Then the server permits this request every time. How I can logout so that the next requests require an authorization again?  Now I tried to use several methods on my server for logout:  @RequestMapping(value = "/logoutMe2", method = RequestMethod.GET) public void logout2() {      SecurityContextHolder.getContext().setAuthentication(null);  }  @RequestMapping(value = "/logoutMe3", method = RequestMethod.GET) public void logout3() {      SecurityContextHolder.clearContext();  }   @RequestMapping(value = "/logoutMe", method = RequestMethod.GET) public void logout(HttpServletRequest rq, HttpServletResponse rs) {      SecurityContextLogoutHandler securityContextLogoutHandler =             new SecurityContextLogoutHandler();     securityContextLogoutHandler.logout(rq, rs, null);  }  @RequestMapping(value = "/logoutMe4", method = RequestMethod.GET) public static void myLogoff(HttpServletRequest request, HttpServletResponse response) {     CookieClearingLogoutHandler cookieClearingLogoutHandler = new CookieClearingLogoutHandler(AbstractRememberMeServices.SPRING_SECURITY_REMEMBER_ME_COOKIE_KEY);     SecurityContextLogoutHandler securityContextLogoutHandler = new SecurityContextLogoutHandler();     cookieClearingLogoutHandler.logout(request, response, null);     securityContextLogoutHandler.logout(request, response, null); }   If I use direct link         I receive a Not Found error.  What I am missing? It seems that I have forget some obvious thing...


I'm a student originally from the West Coast but currently studying in New England. I came across an interesting question concerning dialectology and the use of Patio vs. Porch. I have observed other words like Deck, Veranda, Lanai... etc. Where can I find evidence to show that this is a regional difference or just preference? Thanks!


Auto-sort column Google Spreadsheet on incoming Google Form response

How can I get the Google Spreadsheet to automatically order the incoming form responses alphabetically (2nd column)?   I know how to do this manually or by going in and editing a cell, but cannot get it to do this as an onevent for incoming response.


Say you have a plain text:      How are you today?   and you encrypt it so it becomes:      LKD03Loel03skj1Q03   Now you have multiple people that need to know the plain text of this cipher text but you do not want them to have the same key. It might be they each come up with their own password or they all have a key which identifies that individual.  Now one way of doing this would be adapting  so every user encrypts the one key with their own key so you'd get ten encrypted files (for ten people) of the same key. (I don't know if this is good practice but I think it's a secure option.)  Are there any other ways of having different people using different keys to get the same plain text from the same cipher text (and vice versa)? Is there a special algorithm for this?


What is the proper way to handle the limit with little-$o$?

I was hoping to show that  $$\left(1-\frac{x}{n}+o\left(\frac{2x}{n}\right)\right)^n \xrightarrow{n\to\infty} e^{-x}$$  which would be just fine without the little-$o$.  Trying binomial formula:  $$\left(1-\frac{x}{n}+o\left(\frac{2x}{n}\right)\right)^n = \sum_{k=0}^n \binom{n}{k} \left(1-\frac{x}{n}\right)^{n-k} \left( o\left( \frac{2x}{n} \right)  \right)^k$$  Yet it doesn't look like it leads me somewhere where I could use  $$\frac{o\left( \frac{2x}{n} \right)}{\frac{2x}{n}}\xrightarrow{n\to\infty} 0$$  What is the proper way to handle it?  Edited after the comment by Claude Leibovici.


Part and section in fancyhdr header of (article documentclass)

I'm using the fancyhdr package in an article with the following code  \fancyhf{} \fancyhead[LE,RO]{\thepage} \fancyhead[RE]{\textit{\nouppercase{\leftmark}}} \fancyhead[LO]{\textit{\nouppercase{\rightmark}}}   At the moment \leftmark and \rightmark give the section and subsection titles. My subsections are pretty short and on a two-page spread there's a big chance the subsection title is actually on the page, so I don't need it in the header to refer to it. But I do have several part*s to my document.  I would like to use the part name (on the even pages) and the section name (on the odd pages) like so:  |  15       Third part* title      |      §2 2nd section title    16  | |                                  |                                  | |  Content of the 15th page,       |      Content of the 16th page,   | |  continuing to the next          |      continuing to the next      | |  line.                           |      line.                       | |                                  |                                  | |                                  |                                  | |                                  |                                  | |                                  |                                  | |                                  |                                  | |                                  |                                  | |                                  |                                  |   I'm pasting a MWE for testing purposes  \documentclass[twoside]{article}  \usepackage{fancyhdr} \pagestyle{fancy} \setlength{\headheight}{16pt}  \fancyhf{} \fancyhead[LE,RO]{\thepage} \fancyhead[RE]{\textit{\nouppercase{\leftmark}}} \fancyhead[LO]{\textit{\nouppercase{\rightmark}}}  \begin{document}  \part*{First part title}  \section{First section title}  Abc  \newpage  \subsection{First subsection title}  Def  \newpage  \subsection{Second subsection title}  Ghi  \newpage  \part*{Second part title}  \section{Second section title}  Jkl  \newpage  Mno  \end{document}


First I don't want make an animation. I just want to understand how I can make a Scene and wander around in it with 360°.  I mean .


I saw a post in Quora that stated the above. I'm wondering how come we get a negative I know that the sum is approaching infinity. Does that mean that infinity means approaching zero ? No right? Because infinity in my point of view, just means increasing without bounds. Anyways. am I correct? I always though of infinity more of a concept rather than a number. If anyone can explain why is this, I  would really appreciate it.


Can I recover my data after deleting the partition?

I got a Ubuntu 12.04 key. It corrupted after a sudden power cut and I was not able to open my desktop session. I then tried using an Ubuntu live CD but it was not able to mount my drive.     I tried some commands which were suggested by my friends like fsck etc. There was a bad super block on my drive but it was all in vain. I suddenly deleted my partition by mistake. I did not understand partitioning.   I gave it to a professional for repair and thanks to that Windows 8 Pro is installed on my device by making new partitions. Can I still retrieve my data?


How to determine the sum of a series that is neither geometric nor arithmetic but quadratic or cubic?

How to determine the formula of the sum of a series given its $n$th-term formula like: $$U_n= n^2+n$$  or  $$U_n= 6n^2 -12n + 5$$


How can I run/stop/relaunch an application automatically, at boot/login/some other time?

How do you make a script or app to run or stop running automatically when the system is booted, a user logs on, at a specific time, when a disk is attached, etc.?


Where should the period/full stop go in this instance?

In a sentence that ends with a quoted proper name (of a newspaper), where should the "period" go? Currently it is this:  the “Morning Call”.  ...but that doesn't look right.  Should it be this:  the “Morning Call.”  ...or this:  the Morning Call.


What will happen if I add 2GB more RAM with 4GB in Windows 7 32-bit OS?

I already have 4 GB ram but only 2.43 GB usable in my Windows 7 32-bit OS. If I install 2 GB more with 4 GB of old RAM, is it possible to do that to increase the usable RAM size?


.submit() function not working in jquery

I am facing on problem my submit function not working I don't know where is the problem. I am using laravel framework 5.2 h  $('#CheckImageCount').on('click', function() {   var arr = [];   $('.table-error').find('tr').each(function() {     if ($(this).find('td:eq(1)').find('select').val() != '') {       if ($(this).find('td:eq(2)').find('select').val() == '') {         arr.push('false');       } else {         arr.push('true');       }     } else {       arr.push('true');     }   });   if ($.inArray('false', arr) > -1) {     swal("Alert!", "Please Select Working Hours in right way!")     return false;   } else {     $.ajax({       type: 'POST',       url: 'CheckImageCount',       success: function(resp) {         if ($.trim(resp) == "empty") {           $('.error-1').fadeIn('fast').delay(1000).fadeOut('fast');           return false;         } else {           $("#registerBusiness").submit(); // here i want to submit the form         }       },       error: function() {}     });   } });     My form id is registerBusiness it not submit the form even my page not goto that function here is my form  and submit button  <form id="registerBusiness" role="form" method="POST" action="{{ url('/business-for-sale' )}}">{{ csrf_field() }}   And Submit buttton  <button id="CheckImageCount" type="button" class="btn btn-info">Save And Continue </button>


How to make a half adder for x number of qubits with min. cost?

How to make a half adder for N inputs and getting the output on another x+1 output. Where x is numbers of qubit and N=2^x. please take a example of a circuit(x must be greater then 4 or 5 for example purpose ) for more understanding . Here is the  for 2 qubit half adder.


I have this question on SO:    which I originally asked on CrossValidate, and was migrated. But - that happened 6 years ago, and by now, nobody cares it was migrated: Not CV.SX people, not SO people, and not me.  Now, until a short while ago, the migration notification was smaller, less intrusive and below the message. Now it's more prominent - more contrast from page background, and above the message. (Which is why this is not quite a dupe of ).  Why should anybody be bothered with the migration notice for so long, then?  I suggest a time limit be set for the notice appearing. (I don't care that much about the exact number - let's say, maybe 1 month should be ok.)


Transaction log growing on a mirrored principal

I have a pair of SQL Server 2008 R2 servers hosting a synchronously mirrored database with no witness. This weekend, we had to do some network maintenance so I paused the mirroring. Upon resuming, the principal's status reverted to the usual Principal, Synchronized. The mirror, however, now reads Mirror, Synchronized / Restoring... I don't recall the Restoring... part usually being there.  The transaction log has begun to grow on the principal, as well, despite hourly log backups. This suggests to me that the synchronization process isn't freeing up transaction log space.  What's going on here and how do I fix it?


In a paper whose I am the sole author, should I use "I" or "we"?

When writing a paper whose I am the sole author, should I use "I" or "we" when referring myself?


Find a symmetric matrix $B$ such that for every $3\times 1$ matrix $\text{x}$

Let $A=$ $\begin{pmatrix} 2 & 1 & -1\\ 3 & 0 & 1\\ -2 & 5 & 3 \end{pmatrix}.$  Find a symmetric matrix $B$ such that for every $3\times1$ matrix $\text{x}$,   $$\text{x}^TA\text{x}=\text{x}^TB\text{x}$$  I've tried to take the inverse of $A$ and $\text{x}$ to cancel out, but I get nowhere.   Thanks.


Java Copy Constructor with the "this" keyword

I have a pretty general question about java.  I want to know if there is a simple way to recreate this c++ code in java:  class A  {  public:   int first;   int second;    A(const A& other) {     *this = other;   }  ... }   So basically a copy constructor where you can pass an existing object of A a new object of a in the constructor, and it will copy the contents and build an exact copy of the existing object of A.  trying  class A {   int first;   int second;    public A(A other){             this = other;   }  ... }   sadly doesn't work, since eclipse tells me "this" is not allowed on the left handside of an assignment since it's not a variable.  I know I would achieve the same results doing:   class A {       int first;       int second;        public A(A other){                 this.first = other.first;         this.second = other.second;        }      ...     }   But I would like to know if there is an easier way, since sometimes you have a few more class variables.   Thanks in advance!


Expressing a symmetric polynomial in terms of elementary symmetric polynomials using computer?

Are there any computer algebra systems with the functionality to allow me to enter in an explicit symmetric polynomial and have it return that polynomial in terms of the elementary symmetric polynomials? Can I do this in sage? How do I do it? Thank you.


I have a drive used for my ubuntu machine separate from my computer, and I have to restore data from it in windows. How do I do it without formatting?

I had my raspberry pi 4 (lost due to mistake), and I have to restore its data from my windows computer. It is an SD card, has two partitions:  system-boot USB Drive.  I also know how much windows and Ubuntu's drive formatting is different. So, how do I do it? Is there a tool or any kind of program for supporting two formatting's at the same time? Additional information  I am on windows 10 64bit I used 20.04LTS in past


Compiler error C4430: missing type specifier - int assumed

I have this error:  "error C4430: missing type specifier - int assumed. Note: C++ does not support default-int"  with this code example :  //A.h     #include "B.h" class A{     B* b;     .. };  //B.h #include "A.h" class B{      A* a; // error error C4430: missing type specifier - int assumed. };


Here is a quote: "x Consulting Group provides senior consultants to evaluate, architect and design stable and effective solutions and networks".  What more is it that the consultants are doing that is not already captured by evaluating and designing?


Iterate through all days from a given year

I want to get a list of days List<string> from a given year in the following format: dd.MM.yyyy  public List<string> GetDays(int year) {     List<string> lst = new List<string>();      foreach-day-in-year // TO DO iterate days from given year     {        string day="";         // TO DO  iterate all days         lst.Add(day);     }             return lst; }


Is anything done with the "Send Feedback" (anonymous user feedback) data?

What's done with the anonymous user feedback data?  I get 10k-ers can view it; the data is now available for viewing in the   But does this data serve any purpose for improving the site?  There was a  about what to do with the data, but as far as I can see, nothing has been done.  What purpose does it serve, apart from being recorded─what's it used for?    I see that in , a user states that the message is deceptive and nothing happens to or with it.  Unfortunately, they're suspended, so I don't really think this is a reliable source.  Also,  confirms the data was used in the 2015 Winter Bash.  What about any other time, or, more importantly, now?


Make LaTeX not spell out authors when two similar references exist

I am citing a lot of articles from the same research groups, but with tiny changes to the author lists. To differentiate between these references, biblatex chooses to spell out the authors in my in-text references to avoid ambiguity. However, I would rather like to have biblatex add a letter behind the year.  In short, this:  Some claim (Firstauthor et al 2015a; Firstauthor et al 2015b).   instead of this:  Some claim (Firstauthor & Secondauthor 2015; Firstauthor & Randomauthor 2015).   Is this easily fixed?


sed in-place line deletion on full filesystem?

Due to an application bug as yet undiagnosed, I have several hundred servers with a full disk.  There is one file that has been filled up with duplicate lines—not a log file, but a user environment file with variable definitions (so I can't just delete the file).  I wrote a simple sed command to check for the erroneously added lines and delete them, and tested it on a local copy of the file.  It worked as intended.  However, when I tried it on the server with the full disk, I got approximately the following error (it's from memory, not copy and paste):  sed: couldn't flush /path/to/file/sed8923ABC: No space left on deviceServerHostname   Of course, I know there's no space left.  That's why I'm trying to delete stuff!  (The sed command I'm using will reduce a 4000+ line file to about 90 lines.)  My sed command is just sed -i '/myregex/d' /path/to/file/filename  Is there a way I can apply this command despite the full disk?  (It must be automated, since I need to apply it to several hundred servers as a quick-fix.)  (Obviously the application bug needs to be diagnosed, but in the meantime the servers aren't working correctly....)    Update: The situation I faced was resolved by deleting something else that I found out I could delete, but I'd still like the answer to this question, which would be helpful in the future and for other people.  /tmp is a no-go; it's on the same filesystem.  Before I freed up disk space, I did test and find out that I could delete the lines in vi by opening the file and running :g/myregex/d and then successfully save the changes with :wq.  It seems it should be possible to automate this, without resorting to a separate filesystem to hold a temp file....  (?)


What is the lightest linux os for older computer

I have a computer that has 2 gb ram and not very good other features.I want to run Android Developer Studio on this computer and I want to use linux distribution.Which linux distribution can I use ?  EDIT If I should be more clear, Is LXLE or Lubuntu is good for me or not ?


Use SQL to extract characters with multiple back slashes

I have a string:   \_AAA\DDDD\09090\longtest   How can I extract just the string  09090? There will be many strings like these and I would like to extract the string between the 3rd and fourth back slash.


Can I downgrade from macOS Sierra to Snow Leopard (OS X 10.6)?

I have a 2016 MacBook.  First, OS X El Capitan was installed. Now, I've installed Sierra.  Can I downgrade to Snow Leopard? If I can, is USB method okay?


Suppose I need to mention two nouns in a phrase so that they are joined with either "and" or "or". Do I use "the/a/an" with the both of the nouns or just with the first one?


Is $hh^T$ positive semi-definite ($h$ is a column non-negative vector)?

Is $hh^T$ positive semi-definite? It seems to be positive semi-definite, but I cannot prove it. Please help:)


How different are these function from calculus point of view, f(x)=(x^2-4)/(x-2) and g(x)=(x+2)?

Can't we just simplify f(x) and treat it same as that of g(x)?


Why does Skype suddenly fail to log in? Turns out, it's tor!

I am not sure if I'm looking at a network problem or a bug here. Since the update to 4.2.0.11 my Skype can't connect any more. My room-mate has the same problem. We're both on Ubuntu Raring Ringtail 13.04 on an  in my case. Does anyone have the same problem, or do you know of a bug-report?  (Update: Turns out it's neither a bug nor a network problem. Tor exit-nodes are blocked by Microsoft. See my !)  Both purge-reinstall (including the removal of ~/.Skype) and using the .deb from skype.com (version 4.2.0.11_1) instead of the repositories did not help. Running Skype from the command line did not give additional messages.   I don't know how to decode the log files in ~/.Skype/Logs but the usual logs in /var/log/ show no anomalies. Changing the port Skype uses to one that is forwarded to my machine by the router, did not work either. Nor did running Skype as root.  The fact that I can get it running on the same machine, when I use tethered connection of my mobile points towards a network problem, but then again other machines in our household have no problem at all and I didn't change any network configurations for half a year.


How is a batsman not out when the wicket is put down and they don't have their bat or body grounded inside the crease?

When running between the wickets, a batsman may be run out if they haven't "made their ground" before a fielder throws the ball, or uses their hand holding the ball, to dislodge the bails. Effectively the batsman has to be behind the crease.  However I recently watched a match where a batsman didn't have anything on the ground behind the crease when the wicket was put down, but they were given not out and then continued batting.  What's the story behind this non-wicket? Was the umpire wrong or have the laws changed?


Why do I not have the unsung hero badge?

I just got awarded the "Tireless" badge on StackOverflow, and have inspected my answers to check if I qualify for the "Unsung Hero" badge. I have written a query , that clearly says that 12/30 accepted answers have zero score. That's both more than 25% and 10. Do I have to wait a day after getting the "Tireless" badge before getting the "Unsung Hero" one?


How to calculate the moment of inertia of a solid cube?

How do I calculate the moment of inertia of a uniform solid cube about an axis passing through its center of mass?  I also wanted to know if the moment of inertia of a body is independent of its shape. Also, recently I read somewhere that the moment of inertia of a  uniform solid cube is minimum about an axis passing through its COM because the mass is more concentrated at its center. Does the statement make any sense?


I have got the following android model (Acer DA220HQL) with  Android Ice Cream installed (Android 4.0.4). Unfortunately this version is quite outdated nowadays and all android apps  do not work. I would like to know, if there is any new official Android version or even a custom android rom that would be compatible with this specific model (image attached for better assistance) and which one. That would help me a lot!  Regards


Difference between "the very first" and "first"

I have the sentence:     Who wrote the very first dictionary ever?   Is it any different from     Who wrote the first dictionary ever?   I don't get how something could be more first.


Need 'Ubuntu 15.10 _Wily Werewolf_ - Release amd64 ' on USB

Whenever I try the command sudo apt-get install -f I get the message     Media change: please insert the disc labeled    'Ubuntu 15.10 _ Wily Werewolf_ - release amd 64 (20151021)'    in the drive '/media/cdrom/' and press enter.   Now, my question is can I use a USB instead of a DVD in this case? Because  I've got the .iso named above already on a boot USB.


How to convert java or class file to exe file

I have been created a java app using swing and I want to convert to an exe file how to do it.  public Performance() {     f = new JFrame("Ticket Booking");     f1 = new JFrame("Payment Details");     f2 = new JFrame("Payment Successfull");     l1 = new JLabel("Movies :");     l2 = new JLabel("Timing :");     l3 = new JLabel("Class:");     l4 = new JLabel();     l5 = new JLabel();     l6 = new JLabel("No of Person:");     l11 = new JLabel("Movies :");     l22 = new JLabel();     l33 = new JLabel("Timing :");     l44 = new JLabel();     l55 = new JLabel("Class:");     l66 = new JLabel();     l77 = new JLabel("No of Person:");     l88 = new JLabel();     l99 = new JLabel("Amount:");     l00 = new JLabel();     lsuccess = new JLabel("          Thank u For booking Ticket...");     c1 = new JComboBox(s1);     c2 = new JComboBox(s2);     r1 = new JRadioButton("10:00pm");     r2 = new JRadioButton("1:00pm");     r3 = new JRadioButton("4:30pm");     buttongroup = new ButtonGroup();     b1 = new JButton("Submit");     b11 = new JButton("Pay Bill");     b22 = new JButton("Edit");     t1 = new JTextField(10); }


Moving vectors to specified coordinates in QGIS?

I have a layer of vectors located around, say, (100, 100), and I want to move them to new coordinate like (1000, 1000).   How should I do it using QGIS?


Can you end concentration on a spell during someone else's turn?

Say for example, my group is fighting a group of archers. Bard casts Darkness. We determine that the archers can see through the darkness, as they are hitting each of their shots. Can the bard end concentration on the Darkness spell the moment the party realizes that they can see through the darkness or does he have to wait until his turn?


Python print mystery - How to print without a space

How to have the same functionality as below in Python 2.7. No future please.   print(item, end="")


Singular/plural article for genitive noun

When we have a sentence like      I can identify with a company's products   Does the plural form of the "a" depend on the "company's" or on the "products"? The latter would mean that it had to be a "the" instead but I am simply unsure what word to refer to here.  Bonus points if anyone could recommend me accurate terms to describe this problem because I simply didn't know what to search for


2nd build to PDF stops with 3 errors when previous PDF is still open - Texniccenter 2.02, MikTex,

IT reimaged my PC (Windows 7) and I had to reinstall all the software they don't have on their standard image - including MikTeX and TeXniccenter.  If I try to compile and output a PDF the second time, but I left the last PDF open after viewing it, the compile stops.  See below for information from log file, the LaTeX and Viewer profiles.  I remember having this problem before, and a colleague gave me a solution (other than remembering to close the PDF every time I want to recompile) and that was to change the build profile in some way so that it closed the PDF before the build, but I can't remember where the change needs to be made or what the code is (and the colleague has left).  Thanks for any help.  From log file:  ! I can't write on file `"0 - 10-4 polar curves.pdf"'. Please type another file name for output ! Emergency stop.                      \endgroup \set@typeset@protect  l.35 \myclass  *** (job aborted, file error in nonstop mode)


Matrix of rank 1; show that $A^2=cA$ for some scalar $c$.

Let an $n \times n$ complex matrix $A$ having rank $1$.  Prove that $A^2 = cA$ for some scalar $c$.  What I know is that all matrices having rank 1 have rows based on a scalar multiple of the other. This should probably be enough to figure out a very simple proof but I've been out of academic pursuits for 15 years and am having a hard time shaking the dust off.


I have a big problem with the repositories

I have installed Ubuntu 19.04 Disco Dingo a week ago in my computer. When I try to add a new repository with this command (sudo add-apt-repository ppa:gezakovacs/ppa this is only an example) the terminal shows this text when I do a update with sudo apt-get update.   E: El repositorio «ppa.launchpad.net/gezakovacs/ppa/ubuntu disco Release» no tiene un fichero de Publicación. N: No se puede actualizar de un repositorio como este de forma segura y por tanto está deshabilitado por omisión. N: Vea la página de manual apt-secure(8) para los detalles sobre la creación de repositorios y la configuración de usuarios.     Can you help me? Thank you.


jquery functions inside of dynamically generated html not working

I looked up the load method to find an alternative to php includes. I got the load to add html dynamically and it works. The one issue though is that function aren't working. I think it's either an order issue, structure issue or plain logic. Any help to get my functions to work in dynamically generated html would be greatly appreciated. Sample structure below.  $(document).ready(function () {     "use strict";      $("header").load("/_includes/header.html");  });  $(window).bind("load", function () {     "use strict";      $('.class').click(function () {         $('#id').slideToggle('fast');     }); });


How to validate a specific format phone number?

My numbers looks like (###) ###-####  There is a space between the ) and the next digit or my number can look like (###) ###-#### ext ####  space after the ext and the )  Can someone tell me what regex needs to be performed to verify if either one is valid. Please note that the extension needs to be 4 digits if one is present.  I found this RegEx expression on the web  Regex.Match(number, @"^(\+[0-9]{9})$").Success   Unfortunately I am not very good at RegEx to understand or modify that


How is the return status of a variable assignment determined?

I have seen constructs in scripts such as this:  if somevar="$(somecommand 2>/dev/null)"; then ... fi   Is this documented somewhere?  How is the return status of a variable determined and how does it relate to command substitution?  (For instance, would I get the same result with if echo "$(somecommand 2>/dev/null)"; then?)


Does breaking concentration of the slow spell break its effects immediately?

On your turn, you break the concentration of an (enemy)  spell with your weapon attack.  When exactly does the spell stop affecting you?   At the same moment that the enemy spellcaster loses the concentration or the next turn? Phrased differently: do you get back your extra attacks, your bonus action, and the second half of your movement right away - on the same turn?


A New Source of Stalhrim: Baldor Iron-Shaper just keeps saying "Terrible times"

What can I do to keep Baldor Iron-Shaper from repeating "Terrible times" rather than advancing me to the next stage in the quest?


Why have I not received the Curious badge, even though I have asked 11 positive voted questions?  That's what the badge tracker indicates:      These are my question list.


Name for widget with side-by-side available/selected listboxes?

Two list-boxes, side by side, one with available items, the other with selected items, with arrows in between to move items back and forth.


Lightning Web Components - Benefits and Support

Salesforce announced Lightning Web Components in Dec. 2018. In comparison to the existing Aura Framework:   What are the benefits of using Lightning Web Components? / How much faster are they? Where are Lightning Web Components supported? How are LWC compatible to existing Aura Components?


I want to know which executable gets executed for any command in bash.  Example:     I have firefox installed here /usr/bin/firefox, it is in the $PATH alias browser=firefox alias br=browser   Now I want to type something like getexecutable "br" and it should display /usr/bin/firefox


How should we deal with duplicate answers?

Duplicate questions are "solved" — it's clear what to do with them, there're tools to deal with them... but what happens when two users post the same answer? This happens a fair bit, particularly on questions with simple answers ("Click this button"-type ones).  Do we upvote both answers, since they are both correct? Do we upvote the first one (although if the answers were posted within a few minutes of each other, after an hour it's impossible to tell as they both show up as "answered 1 hour ago")? Do we upvote the currently highest voted one? Do we upvote one and downvote the other? Do we flag one (seems a little excessive)? Something else?


Prove by induction that $b_n-a_n < (\frac {1}2)^n(b-a)$

For two numbers $a$ and $b$ with $0 \leq a\leq b $ we have that: $a_{n+1} =\sqrt{a_nb_n} \quad$ , $\qquad b_{n+1} = \frac {a_n+b_n}2 \quad,$ $\qquad a_0 = a, \quad b_0=b $ And I have to prove for $n\ge1$ that $b_n-a_n < (\frac {1}2)^n(b-a) \quad $ if $a\neq b$ In previous exercises I've proved that: (i) $\sqrt{ab} \leq \frac{a+b}2$ $\quad$ for $\; 0\leq a \leq b \;$ with equality if and only if $a=b$ (ii) $ a <\sqrt{ab} \; $ and $\frac{a+b}2 <b \; $ for $0 \leq a<b$ By using (i) and (ii) I have done this so far: $b_n-a_n =\frac{a_{n-1}+b_{n-1}}2 - \sqrt{a_{n-1}b_{n-1}} $ $\qquad \quad < \frac{a_{n-1}+b_{n-1}}2-a_{n-1}=\frac{1}2(b_{n-1}-a_{n-1}) \quad$ for $n\ge1$ I'm stuck from here. (Edited)


I remember watching in Cartoon Netwoorks years ago maybe around the 2000's a cartoon about diferent alien races living in diferent planets where each race was related with an element like rock people, ice, people, fire people and another. I also remember that the first episodes where about their star dying and converting in a supernova killing their planets and they end escaping to the space in ships.  I have been years trying to find what cartoon was?


Figure references with the word Figure and not just a number

I reference figures this way: \label{fig:hello} and then just \ref{fig:hello} but the latter returns only the number without the word "Figure". How can I get the word Figure such as "Figure 1"?


determining an integral using only derivative properties

Please note that this question is different from a similiar one as although the basis is the same, the integral that is being calculated is different.  let $\alpha′(x)=β(x),β′(x)=α(x) $ and assume that $\alpha^2 - \beta^2 = 1 $. how would I go about calculating the following anti derivative : $\int\alpha^2(x)/\beta^4(x) dx $.  I have tried several methods which did not work. These included putting the integral in terms of one of the variables using the first given condition and then trying to apply an U-substitution. However, since both $\alpha(x)$ and $\beta(x)$ are raised to even numbered powers, I end up with either an $\alpha'(x)$ or $\beta'(x)$ which makes it such that I cannot U-substitute since I cannot rewrite the entire integral in terms of U.  I would appreciate any help.  Thank you.


"happen to be" and "happen to have" - expressions of probability?

Based on Logman dictionary:       happen to do something: if you happen to do something, you do it by chance.   for example take a look at these examples:     They happen to be unemployed at the time. I happen to have a degree in computer science.    So based on the definition of the happen to do something, first one means they are probably unemployed at the time. and the second one means I probably have a degree in computer science.     Am I right?


Let $G$ denote the set of edges between vertices $1,...,N$ such that $G$ connects all vertices, i.e., for any distinct vertices $x,y =1,2,...,N$, there exists a connected paths in $G$ from $x\mapsto y$. Then how would one prove $$ \sum_{G}(-1)^{|G|} = (-1)^{N-1}(N-1)!, \quad N\ge 1 $$ where $|G|$ is the number of edges of $G$


Proof that any simple connected graph has at least 2 non-cut vertices.

I'm trying to prove that any simple connected graph with at least $3$ vertices ($|V| \ge 3$) has at least $2$ vertices whose removal will not lead to the increment of number of components. In other words, there are at least $2$ vertices that are non-cut vertices.  Attempt at solution:   I tried to prove it using induction by the number of vertices: $n - t \ge 2$, where $n$ is the number of vertices our graph has, and $t$ is a number of cut vertices.   Base  Let $n =3$, then the graph will look like this:  $О-О-О$  Clearly, it has one cut vertex (the middle one). So, $3-1 \ge 2$ holds.  Or it can be a full graph, then $3 - 0 \ge 2$ also holds. Assumption  Let $n = k$, and the formula holds, $k - t >= 2$ Step  Prove for $n = k + 1$ If we add one vertex to the graph, it could either be a cut vertex or non-cut vertex. In case it is a cut vertex, we have $$\begin{align*}&(k+1) - (t+1) \ge 2\\ &k + 1 - t - t\ge 2\\ &k\ge 2\end{align*}$$   In case it is not a cut vertex...and I'm stuck here, because anything can happen. The number of cut vertices might increase, might decrease, or stay the same.  I'm sure there is better and shorter proof to this, and I really hope someone could help me.


Shortest one-line shell script to print all special characters

I'm looking for a shortest one line shell script to print all special characters in ASCII table (from chr(32) --> chr(127)) Thanks for all your help & support!


Conformal automorphism of unit disk that interchanges two given points

Let $a$ and $b$ be distinct points in the unit disk $D$. Show that there exists a conformal automorphism $f$ of $D$ that interchanges $a$ and $b$; that is, $f(a) = b$ and $f(b) = a$.  Idea: we know that $g(z)=\frac{\alpha-z}{1-\bar{\alpha}z}$ interchanges $0$ and $\alpha$ and by composition we can find out the map $f(a) = b$ for any $a$ and $b$ in the unit disk $D$. But how can I get the other way by the same map? Thanks.


I have four functions $f_1,f_2,g_1,g_2:\mathbb{N}\rightarrow\mathbb{R}^+$. Suppose that $f_1\in\Theta(g_1)$ and $f_2\in\Theta(g_2)$. I need to prove that $f_1+f_2\in\Theta(\text{max}\{g_1,g_2\})$.   This is fairly easy to see with a specific example such as the following:  Let $f_1=x+5$. Then $f_1\in\Theta(x)$.  Let $f_2=2x^2$. Then $f_2\in\Theta(x^2)$.  $f_1+f_2 = (2x^2)+(x+5)$ which  is $\in\Theta(x^2)$ and $x^2$ is the max of $x$ and $x^2$.  I cannot figure out how to write this as a general proof.  I can say that $f_1+f_2\in O(\text{max}\{g_1,g_2\})$ since I want a bigger value of $g$.  I am having trouble saying that $f_1+f_2\in\Omega(\text{max}\{g_1,g_2\})$ since I don't necessarily know that with a bigger value of g the inequality of $\Omega$ will still apply.


Transparent rendered object over tracked background

I am ready to render my animation but it seems i have a problem with my texture of the object i animated.  In the image u can see that the object is transparent and I can look trough it. So what is the problem here?   This is the node setup.    Thank you for your help!


Switches needed in an n-location multiway switching system

we can construct a two location multiway switching system with two 3-way switches:    They also teach us how to perform three location multiway switching with two 3-way switches and one 4-way switch:    Is it possible to make a similar system (three locations, all able to switch the light in any situation) with only three 3-way switches?   What can be said in general about the switches needed to make an n-location multiway switching system?


How do i prove invertibility of this linear transformation

Let $T$ be a linear transformation from a vector space $V$  over reals into $V$ such that $T-T^2=I$. Show that $T$ is invertible


Nothing looks right in the ASCII art.  It looks wrong and nothing is proportional, how do I fix this? I have tried fiddling with my font size, but nothing still looks right!


Exposure level indicator in the top panel not showing correct exposure on Canon 7DMKII

The exposure level indicator on the LCD monitor in the back of the camera is working as it should. The problem is that the exposure level indicator on the LCD panel on the top of the camera is always locked to zero. I've attached a photo showing the problem and the camera settings used are only for demonstration purposes.   If you look at the attached picture, you can see that in these light conditions and with the current camera settings, the picture will be overexposed 1 level. The LCD panel on the top is showing that the picture is exposed correctly and it's not. Have anyone experienced this? I've reset the settings of the camera and updated the firmware to the latest version, nothing helps.


Why does this sentence use "does not" instead of "do not"?

I have two sentences that I was unsure if I needed to use "do not" or "does not". Now I know that the correct one is the one with "does not" but I don't understand the reason why. The two sentences are as follows:  Nevertheless, having those skills does not automatically guarantee their performance as marketers.  Nevertheless, having those skills do not automatically guarantee their performance as marketers.  The rules is that you use "do not" with words that are plural and "does not" with words that are singular. In my mind, "those skills" is "they". And they do not.  I don't understand why "those skills" is "It". It does not.  Someone told me that the reason that "does not" is the correct option is because of the word "having". But I don't understand the reason or if there is a rule. Is this correct? If so, why? And if not, can anyone please explain? Thank you.


How can I google search a defined set of domains/sites for a certain string

I want to search for a string and limit that search to certain sites.  For instance I may want to search   Google TV site:walmart.com Google TV site:amazon.com Google TV site:bn.com Google TV site:bestbuy.com Google TV site:toysrus.com   I want to be able to type in the string each time, but limit the search to those domains, it's ok if each are in a seperate window.  Any ideas?


How to determine if JS code executes in iframe?

How can I determine whether a script executes in iframe or not? The solution should work in Android, iOS, Windows Mobile browsers.  Is it possible or not?


Getting NullPointerException when trying to create RMQSink on Flink

I'm trying to make Sink for Flink to be able to send messages from Flink to RabbitMQ. When I create Sink in main, everything works fine - I receive a message on the special queue on RabbitMQ. Unfortunately, when I try to create Sink outside the main method - it ends with NPEx (Flink shows, that StreamExecutionEnvironment is null).  Code which works have one disadvantage - it can send a message only once when starting .jar on Flink. I want to have a function which will allow me to send a message to RabbitMQ when calling this function.  Here is code which works:  public static void main(String[] args) throws Exception{  RMQConnectionConfig connectionConfig = new RMQConnectionConfig.Builder()         .setHost(RABBITMQ_HOST_NAME)         .setPort(RABBITMQ_PORT_NUMBER)         .setUserName(RABBITMQ_USERNAME)         .setPassword(RABBITMQ_PASSWORD)         .setVirtualHost(RABBITMQ_VIRTUAL_HOST)         .setConnectionTimeout(5000)         .build();  StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();  SimpleStringSchema simpleStringSchema = new SimpleStringSchema();  DataStream<String> dataStreamSource = env.addSource(new RMQSource<String>(         connectionConfig,         KURA_QUEUE_NAME,         simpleStringSchema));          env.fromElements("ALERT")         .addSink(new IotRMQSink(connectionConfig,                 ANDROID_QUEUE_NAME,                 simpleStringSchema));  dataStreamSource.filter(new TemperatureFluctuationDetector());  env.execute(); }   And here is code which I want to look like (but throws NPEx):  public static RMQConnectionConfig connectionConfig; public static StreamExecutionEnvironment env; public static SimpleStringSchema simpleStringSchema;  public static void main(String[] args) throws Exception{  connectionConfig = new RMQConnectionConfig.Builder()         .setHost(RABBITMQ_HOST_NAME)         .setPort(RABBITMQ_PORT_NUMBER)         .setUserName(RABBITMQ_USERNAME)         .setPassword(RABBITMQ_PASSWORD)         .setVirtualHost(RABBITMQ_VIRTUAL_HOST)         .setConnectionTimeout(5000)         .build();  env = StreamExecutionEnvironment.getExecutionEnvironment();  simpleStringSchema = new SimpleStringSchema();  DataStream<String> dataStreamSource = env.addSource(new RMQSource<String>(         connectionConfig,         KURA_QUEUE_NAME,         simpleStringSchema));  publish();  dataStreamSource.filter(new TemperatureFluctuationDetector());  env.execute(); }  public static void publish(){     env.fromElements("ALERT")         .addSink(new IotRMQSink(connectionConfig,                 ANDROID_QUEUE_NAME,                 simpleStringSchema)); }   It looks like StreamExecutionEnvironment is null, but I set it in the main function. Does anyone have an idea how can I avoid this NullPointerException?


How do I disable 3D anaglyph display mode in Minecraft?

My game has gone into 3D anaglyph red-cyan mode and I don't know how to return it to its normal screen.


The difference between webpart and add-ins

From what I know both of web part and add-ins (SharePoint-hosted add-ins) can give a custom functionality to a SharePoint page. And the only differences I know is that web part can be added via server-side control and reusable to any pages in a site. And for SharePoint-hosted add-ins, we need to install the add-ins first. But we can add add-ins as a part of a page too right? **pardon me if i'm wrong   So what's the other difference between them?