Set border of parent  depending on 2 child

I want a border around a
 with 2 child elements. At the moment the green border is just at the top and not all around the
 container. Can you tell me how to fix this issue?   Here you can see my code:    .frame {     border-style: solid;     border-color: green;     width: 500px; } .left {     float: left;     min-height: 20px;     width: 200px;     min-height: 20px; } .right {     float: right;     min-height: 20px;     width: 300px; } .entry {     height: 20px }

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Integral inequality problem (cauchy-schwarz)

Prove that any continuously differentiable function $f : [a,b] \rightarrow R$ for which $f(a) = 0$ satisfies the following inequality $$\int^b_a f(x)^2dx \leqslant (b-a)^2 \int_a^b f^{'}(x)^2dx$$ By looking at it, I think we need to apply the Cauchy-Schwarz inequality but I am unable to go any further. Any help is appreciated. Thanks in advance.


I wish to  include eps images generated from Matlab plot (pdf is generated by Matlab as a whole page, that's why eps), however the conversion fails, leaving blank pdf image. The messaghe is:  MiKTeX GPL Ghostscript  9.25: Unrecoverable error, exit code 1    Sorry, but "MiKTeX EPS-to-PDF Converter" did not succeed. The log file hopefully contains the information to get MiKTeX going again: C:\Users\Andrey\AppData\Local\MiKTeX\2.9\miktex\log\epstopdf.log   The content of the log file  2019-12-03 06:29:05,797+0100 INFO  epstopdf - starting with command line: epstopdf --outfile=images/kkk-eps-converted-to.pdf images/kkk.eps 2019-12-03 06:29:06,456+0100 FATAL epstopdf - Invalid argument 2019-12-03 06:29:06,457+0100 FATAL epstopdf - Info:  2019-12-03 06:29:06,457+0100 FATAL epstopdf - Source: Libraries\MiKTeX\Core\Stream\FileStream.cpp 2019-12-03 06:29:06,457+0100 FATAL epstopdf - Line: 68   I have recently installed and updated Miktex and compile with LuaLatex.  Here is the  content of the eps, if needed   What is wrong with it? I have no idea what to do about it.  Update  First of all I'd like to that I do compile with --shell-ecape (from TexStudio)  Process started: lualatex.exe --shell-escape -synctex=1 -interaction=nonstopmode    I tried suggestion from Christian Shenk. The command is   mgs.exe -q -sDEVICE=pdfwrite -dSAFER -dAutoRotatePages=/None -dPDFSETTINGS=/prepress -dMaxSubsetPct=100 -dSubsetFonts=true -dEmbedAllFonts=true -sOutputFile=images/kkk-eps-converted-to.pdf - -c quit   I tried to execute it  in command processor. It creates a 0 byte pdf file and gets  stuck.  Update 2  I executed  epstopdf --outfile=images/kkk-eps-converted-to.pdf images/kkk.eps   And I did get additional information  Error: /invalidfont in /findfont Operand stack:    Helvetica-BoldOblique Execution stack:    %interp_exit   .runexec2   --nostringval--   --nostringval--   --nostringval- -   2   %stopped_push   --nostringval--   --nostringval--   --nostringval--   false   1   %stopped_push   2015   1   3   %oparray_pop   2014   1   3   %oparray_pop   --nostringval--   1998   1   3   %oparray_pop   1884   1   3   %oparray_pop   --nostringval--   %errorexec_pop   .runexec2   --nostringval--   --nostringval--   --nostringval--   2   %stopped_push   --nostringval--   1967   1   3   %oparray_pop Dictionary stack:    --dict:973/1684(ro)(G)--   --dict:0/20(G)--   --dict:123/200(L)-- Current allocation mode is local   I have no clue how I can fix it. It mentions something about "Helvetica-BoldOblique", but the images don't use it, but regular Helvetica.


"Highly active question" banner is misleading

Today I noticed this banner on :   What exactly is that supposed to mean? I do NOT think it means this is a highly active question, and I very much doubt it ever was.  As seen in the line above, it was last active 1 year, 11 months ago, the moment it was asked.  The Q&A  today and another Nov. 19 (17 days ago), Aug 21 (107 days ago), and January 8 2018 (697 days ago). As far as I can tell, it never made the HNQ list.  Neither the question, nor its sole answer posted simultaneously, were ever edited, nor were they ever commented on.   Why is this being characterized as "highly active?"  Can that inaccurate wording be fixed to better reflect reality?


LS_COLORS settings for specific types of files

I'm trying to set up my color scheme for ls, and I'm having trouble finding information about exactly what parameters I have to work with, or where those come from. And especially setting colors for types of files instead of based on filetype.  For example, this is my current color scheme: LS_COLORS='di=34;01:fi=0:ln=96;1:pi=36;1:so=31;1:bd=5:cd=5:or=31:mi=0:ex=35'  I found those parameters (di, fi, etc) from a website tutorial. But where do those come from? Can I set custom ones? I know I can set colors like *.jpg=0 and such. But is there a way to do it based on types of files? I specifically want to set compressed file types, but if I have to do it by recognizing filetypes, I feel there's a better way.


I need to make an id with a specific  format  where 2 first digit are year, and the rest are just incremental number with 000 as spacer between year and incremental number where the qty of 0 will decrease along with increasingly incremental number such as 190001,190002,.....,190180,...,191400.  All i can think of using   $id = ''; if(srtrlen($number) == 1){    $id = date('y',time()).'000'.$number; } elseif(strlen($number)==2){    $id = date('y',time()).'00'.$number; } . . . else{    $id = date('y',time()).$number; }


Can 1/2" drywall support recessed 7lb speakers?

I recently purchase some JBL SP8II wall-mount speakers that I would actually like to use in the ceilings. However these speakers don't come with a between-the-studs support of any kind (there is a wall bracket but it's a flimsy plastic that wouldn't add any support for a ceiling mount situation).   Do you think my 1/2" drywall ceilings would support these 7lb speakers without creating sag? The installation instructions are basically to cut out a 8"x10" rectangular hole in the drywall and then put the speakers in that hole, mounting them to the drywall.   Thanks in advance!


Let $(a_k)_{k \geq 1}$ and $(b_k)_{k \geq 1}$ be two strictly positive sequences such that $$\frac{a_{k+1}}{a_k} \leq \frac{b_{k+1}}{b_k}$$ I have to prove that if $\sum_{k=1}^\infty b_k$ converges, then $\sum_{k=1}^\infty a_k$ must converges as well. I found that $a_k \leq C b_k$ for $C > 0$. So if $\sum_{k=1}^\infty b_k$ converge, then $\sum_{k=1}^\infty C b_k$ converges as well. It is not clear for me that $\sum_{k=1}^\infty a_k$ must converges using the squeeze theorem. The best I have so far is $$0 \leq \sum_{k=1}^n a_k \leq \sum_{k=1}^n C b_k$$ So $$0 \leq \sum_{k=1}^\infty a_k \leq \sum_{k=1}^\infty C b_k = L \in \mathbb{R}$$ But nothing specify $L=0$. Am I missing something?


What was Ash trying to do with the magazine?

In the movie Alien, Ash      turns out to be an android. At one point, he freaks out, rolls up a magazine, and stuffs it into Ripley's mouth.    What in the world was he trying to do?


Script that exports enviromental variables cannot export them

I have the following script named export.sh:  #!/bin/bash  SOURCE="${BASH_SOURCE[0]}" while [ -h "$SOURCE" ]; do # resolve $SOURCE until the file is no longer a symlink   DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"   SOURCE="$(readlink "$SOURCE")"   [[ $SOURCE != /* ]] && SOURCE="$DIR/$SOURCE" # if $SOURCE was a relative symlink, we need to resolve it relative to the path where the symlink file was located done  SOURCE=$(dirname ${SOURCE})  export $(cat "${SOURCE}/../params.env" | xargs)   In some words what it does it to export enviromental variables from a file named params.env that is located by convention on the prarent folder and exports the contents as enviromental variables.  Sample contents of params.env file are:  SOMEVAR="val1" SOMEVAR2="val2"   And a successfull run will provide me SOMEVAR with value val1 and SOMEVAR2 with value val2 enviromental variables.    But if I run:  ./export.sh   And afterwards  printenv | grep SOMEVAR   It does not show that the enviromental variable is set.


Populate an entire pre-configured workspace in i3wm

Is it possible with I3Wm to populate an entire workspace with determined size, position and commands for each window?  I know I can do i3-msg "exec xterm -e 'ls; bash'" to create a new window, but I can't specify his position and size.  Maybe there is also an alternative by declaring via JSON the layout or something like that?


Could someone please tell me what font this is? It looks so beautiful and elegant. Particularly, look at the square root symbol and the \pi. I have been looking for this font for a very long time, but to no avail. The pi you see in the image is a part of the universal math font, which I have in Word, but am unable to import it in XeLaTeX. Please let me know which font this is.


In the movie Donnie Darko, where does the jet engine in the beginning of the movie come from originally?


Setting up the default AspNetSqlProvider to point to remote database

When starting a new project that required the use of membership providers I found that I could not connect to a remote database that contained the membership database.  I ran aspnet_regsql and was able to create the membership database on the remote server but when I go to ASPNET Configuration (cassini development server) it will not connect to the remote server.


About some properties of composites of field extesions

When I'm self-studying  Parick Morandi's book Field and Galois Theory,I came across some problems,which I can't work out fully. Let $K$, $L$, be two extension fields of base field $F$. If  $K/F$ and $L/F$ are both Galois extension ,how to proof that their composite $KL$ is also Galois over $F$. And why we have the same conclusion when "Galois "is replaced by "normal","separable","purely inseparable",or "algebraic"? I worked on these problems and searched this website  for two days but could only proof the cases for "separable","purely inseparable",and "algebraic".I have no idea how to proof the "normal" and "Galois" cases. In addition ,why the degree inequality  holds for $$ [KL:F]\leq[K:F][L:F]$$ If you know how to proof these ,please tell me.I am here waiting for the answers.Thank you!


I just got awarded the third "Custodian" badge on StackOverflow. Given my current reputation (< 800) I have access to two review queues only. So where did the third badge come from?   When taking a deeper look into my badge history, I got awarded one Custodian badge for reviewing late answers and one for reviewing first posts. The third badge I got was for reviewing an edit made to one of my answers.  Is this the purpose of the Custodian badge - or should it just be awarded for reviews of changes made to other people's posts for >2k users?


I typed the following and get an error. Help would be appreciated it. $x^{2}\lneq x$ It states undefined control sequence.


Show that $\cot{142\frac{1}{2}^\circ} = \sqrt2 + \sqrt3 - 2 - \sqrt6$.

Show that $\cot{142\frac{1}{2} ^\circ} = \sqrt2 + \sqrt3 - 2 - \sqrt6$.   What I have tried: Let $\theta = 142\frac{1}{2}^\circ \text{ and }  2\theta = 285^\circ$. $$\cos 285^\circ = \cos 75^\circ$$ $$\cos 75^\circ = \frac{\sqrt3 - 1}{2\sqrt2}$$ $$\cot \theta = \sqrt{\frac{1 + \cos 2\theta}{1 - \cos 2\theta}}$$ From here, pls help me proceed further. Thank you :)


I am trying to create folder in the drive with the username:zedaan . I have try to chmod the drive still the same issue sudo chmod -Rf 777 /media/1666675566673521  Here are the drive lists:


Looking for a good book on Differential Equations

I know many of you are tired of book recommendation posts and questions. But I am self learning Theoretical Physics, and I am having a hard time choosing a book to learn differential equations (ODEs). I really want a good understanding of differential equations; I have been told that ODEs and PDEs are the language of physics. Anyways, if you could be so kind to give me some good recommendations, I would truly appreciate it. I thank you if you read my question and hope you have a wonderful rest of the day. PD: I new to this site, so this is essentially my first post. I was checking the h bar chatroom. I hope to one day gain the knowledge that you guys have. Truly mesmerizing community. I hope to grow in this environment.


Laptop charger leaks AC while giving DC voltage at the same time. How?

So, I got some laptop charger from my neighbor and I was thinking about to do something with it. Then one day I feel tiny shock from the output of the charger. I thought ac to dc filtering mechanism maybe shorted. Then I had tested other remaining charger to see if there was any AC current going on. And they all do the same. Is it normal to have flow some AC through DC ? Can I do something about it ? make it safer for work ? It does not feel like comfortable.


App question timer shouldn't kick in until submission

I attempted to ask a question using the iOS app, but it was rejected due to lack of a required tag. On adding the tag I found that I wasn't permitted to submit the question for another 60 seconds, even though this wasn't a new question.  Is this timer intentional, or should it not kick in for edits of questions not actually accepted by the site?


Windows 10 option in ubuntu grub not working

I've been trying to dual boot Windows 10 / Ubuntu on my Lenovo Ideapad 320, so I first install Windows 10 (legacy), then installed Ubuntu 18.04 (and 17.04)(also legacy).   In the process of installing, Ubuntu installed GRUB. Now after installing Ubuntu, when I restart my laptop, the pink-ish screen of Ubuntu appears with the GRUB, and there is a "Windows 10" option in the GRUB.  When I tap that "Windows 10" option, after some lights off & on, the GRUB appears again and I can't go back to Windows by any means. I've been stuck with this for 2 days, tried many times with no avail.   How do I get back my Windows Boot Loader or How can I go back to Windows? What seems to be the problem? I've Secure Boot disabled.


Misconfigured Compiz and lost desktop usage

I disabled something in the compiz manager, I think I disabled the openGL plugin. Now nothing is showing on my desktop, I can not interact with anything and all I can see is the background wallpaper. The bars are gone, the icons. I've tried resetting the unity, but it did not work. I reinstalled Ubuntu and it also failed. What can I do now? Help me!


C++ Cannot construct class that extends template

Why can I typedef a template and construct it without declaring a constructor, but can't extend a template as a class and construct it without declaring a constructor? In this example, the typedef works but the class does not. Surely somewhere C++ is generating a constructor for the typedef - why can't it do the same for the class? #include <iostream> #include <string>  template <class T> class Event {     public:         Event(T data){this->data = data; std::cout<<data;}         virtual ~Event(){}         T data; };  typedef Event<std::string> StringEvent;  class MyEvent : public Event<std::string> {};  int main() {     StringEvent event("hi"); // ok     MyEvent event2("hi");    // no           return 0; }  Output main.cpp: In function ‘int main()’: main.cpp:21:24: error: no matching function for call to ‘MyEvent::MyEvent(const char [3])’      MyEvent event2("hi");                         ^ main.cpp:14:7: note: candidate: MyEvent::MyEvent(const MyEvent&)  class MyEvent : public Event<std::string> {};        ^~~~~~~ main.cpp:14:7: note:   no known conversion for argument 1 from ‘const char [3]’ to ‘const MyEvent&’ main.cpp:14:7: note: candidate: MyEvent::MyEvent(MyEvent&&) main.cpp:14:7: note:   no known conversion for argument 1 from ‘const char [3]’ to ‘MyEvent&&’


Why is the first line comment of .sh file necessary?

I was told that the first line shebang (#!/bin/bash) is necessary in the shell script file, and the file won't run accurately without this line. But I tested some scripts. They work just fine without that line.  Is that line simply a comment? Does bash omit this line, as it does with other comments? Or does bash interpret it?  Is that line forced in that format? Or just a helpful readable note? What if I put it in other way, say, without the !?


I am not getting security questions while recovering account in gmail, What should i do?

I was logging in to my google account and forgot my password and last password, didn't added any recovery phone number or email. I know when i created the account but google isn't asking me questions, what should i do?


Give the three numbers that form a geometric sequence.

Three numbers form a geometric sequence. If 5 is added to the second term, then the resulting numbers will constitute an arithmetic sequence. If 22.5 is added to the third number, these numbers will again form a geometric sequence. Find the original numbers.


All the code boxes are appearing as 1 line to me. This:  #include <stdio.h>  int main() {     printf("Hello, world!\n");     return 0; }   Appears thus:  #include <stdio.h>  int main() {     printf("Hello, world!\n");     return 0; }   ...which is making the longer code posts harder to read. Someone posted a binary search tree, which was just impossible to read like that.  It appears correct in the preview as I write this.  Firefox 3.6.3, Gentoo Linux 2.6.32  Edit: To clarify: The correct version (with newlines) appears briefly on both Stack Overflow and Meta, but as soon as syntax highlighting is applied (which is almost instantly), then it collapses to 1 line.  This applies to the editor in the "edit question" part, but it seems to be a bit lazier about applying syntax highlighting. (It seems to do it when the box you type in loses focus, so as I'm typing this, it appears correctly, with no syntax highlighting, and when I un-focus the text area, a few moments later, it syntax highlights and collapses to 1 line.)


NPE in own realization of LinkedList (Java)

I'm a beginner in programming and I need to write some kind of own LinkedList, but only with add(E element) method and with Iterator's hasNext() and next(). Here is my code:    public class LinkedArray<E> implements Iterator<E> {          private int size = 0;          private int current = 0;          private Node<E> first;          private Node<E> last;          private Objects[] objects = new Objects[10];          public void add(E value) {             Node<E> element = new Node<E>(last, value, null);             if (last != null) {                 element.next = element;             } else {                 first = element;             }             last = element;             size++;         }          @Override         public boolean hasNext() {             boolean result = false;             try {                 if (objects[current + 1] != null) {                     result = true;                 }             } catch (ArrayIndexOutOfBoundsException e) {                 result = false;             }             return result;         }          @Override         public E next() {             E result;             try {                 current++;                 result = (get(current - 1));             } catch (ArrayIndexOutOfBoundsException a) {                 throw new NoSuchElementException("No more elements in list.");             }             return result;         }     public E get(int position) throws NullPointerException {         Object result;     if (this.objects[position] != null) {         result = this.objects[position];     } else {         throw new NullPointerException("Position is empty.");     }     return (E) result; }           private class Node<E> {              private E element;              private Node<E> next;              private Node<E> prev;              Node(Node<E> prev, E element, Node<E> next) {                 this.element = element;                 this.next = next;                 this.prev = prev;             }         }     }   But when I started to test add(E value)...  @Test     public void test() {         LinkedArray<String> arr = new LinkedArray<>();         String string = "Test";          arr.add(string);         String result = arr.next();          assertThat(result, is("Test"));     }   ...I only get an error. What the problem is, why am I getting it wrong?


I am trying to add a simple console as a panel, but I don't get it working (have a look at the end of the code):  super.setSize(600,4*46);     super.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); pane = super.getContentPane(); GridLayout flo = new GridLayout(4,1,20,2); pane.setLayout(flo); pane.setBackground(grey);  // 1: STOP button JPanel row_cmd = new JPanel(); FlowLayout flo_row_cmd =  new FlowLayout(FlowLayout.CENTER,10,1); row_cmd.setLayout(flo_row_cmd); row_cmd.setBackground(grey_pale); STOP.addActionListener(this); STOP.setBackground(red); STOP.setForeground(yellow); STOP.setFocusable(false); ft= STOP.getFont(); ft=new Font(ft.getFontName(),Font.BOLD,14);  STOP.setFont(ft); row_cmd.add(STOP); pane.add(row_cmd);  // 2: communication  // 3: progression  // 4: console Console console = System.console(); //FlowLayout flo_row_con =  new FlowLayout(FlowLayout.LEFT,10,10); //row_con.setLayout(flo_row_con); //row_con.setBackground(grey_pale);  frame.getContentPane().add(console); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  //pane.add(row_con); //pane.validate(); setVisible(true); ???   How could I do? I don't have much experience with GUI components. Thank you.


Citations not working, bibliography not showing

I assume the bibliography only shows the cited sources, so the real root of the problem is with the citation, but I'm not sure. This is what I have in my latex document now.  . . .  \usepackage[sorting=ydnt,bibstyle=ieee]{biblatex} \addbibresource{uni.bib}  \pagenumbering{plain}  \makeindex  \begin{document}  . . .  miscellaneous citation \parencite[see][page 72]{example}  \newpage  \pagenumbering{roman} \setcounter{page}{1}  \fancyhf{} \fancyhead[LE,RO]{Bibliography} \fancyfoot[LE,RO]{\thepage}  \printbibheading \printbibliography  \end{document}   And in uni.bib (same directory)  @book{example,     author = {Author, Example},     title = {Example Book},     year = {2020},     PUBLISHER = {Example Publisher}     }   This seems like it should work, but the citation reads "miscellaneous citation [example]" and the bibliography section is just an otherwise empty page that says "Bibliography". Note that "\addbibresource{uni.bib}" is shown in bold and entirely yellow (my colour for latex commands). This is probably something pretty obvious, but it still eludes me. I've looked through forums and found nothing that worked, and so I come here seeking your help.


Prove that the eigenvalues of a block matrix are the combined eigenvalues of its blocks

Let $A$ be a block upper triangular matrix: $$A = \begin{pmatrix} A_{1,1}&A_{1,2}\\ 0&A_{2,2} \end{pmatrix}$$ where $A_{1,1} ∈ C^{p \times p}$, $A_{2,2} ∈ C^{(n-p) \times (n-p)}$. Show that the eigenvalues of $A$ are the combined eigenvalues of $A_{1,1}$ and $A_{2,2}$  I've been pretty much stuck looking at this for a good hour and a half, so any help would be much appreciated. Thanks.


sugar daddy sent me check for $3000, i’m waiting for it to clear but he’s asking me to send $500 to a friend

so i’ve been messaging a sugar daddy back and forth. we agreed on a certain amount of money a week but he ended up saying he was going to send me 3x the amount of what we agreed on. he told me i was going to do something with that money, a way for him to trust me. basically he ended up saying i would keep the rate we agreed on first and then pay his friend the remainder. i wearily agreed. so he sent me the check for $3,200 and i’m waiting for it to clear, they estimate 4 days. my sugar daddy is assuring me saying the check will clear and to send $500 to his friend because it’s urgent. something about his daughters health. is it a scam?


I was given a cryptography question during an interview the other day and I couldn't come up with a valid answer. Imagine you are given an efficient algorithm which for a given RSA public key (n,e) is able to decrypt 1% of the messages encrypted with that key. 1% means that the algorithm will deterministically decrypt 1% of all possible ciphertexts on the first call, and will never decrypt the other 99% of all possible ciphertexts with any number of invocations. Figure out an algorithm that uses this one and can decrypt any message.   Any ideas ?


Casting a function pointer to another type

Let's say I have a function that accepts a void (*)(void*) function pointer for use as a callback:  void do_stuff(void (*callback_fp)(void*), void* callback_arg);   Now, if I have a function like this:  void my_callback_function(struct my_struct* arg);   Can I do this safely?  do_stuff((void (*)(void*)) &my_callback_function, NULL);   I've looked at  and I've looked at some C standards which say you can cast to 'compatible function pointers', but I cannot find a definition of what 'compatible function pointer' means.


How can I duplicate my existing software packages on a new system?

I installed 12.04 in a separate partition. Right now, I would like to install the software that I have installed on my 10.04 in my 12.04 too. I was hoping there would be a workaround for this using aptonCD. But I figured out 'restoring' using apt on cd only copies the .debs into the cache file and that might mess things up for me considerably.  The rough idea that I have is :   Run an 'apt' command on 10.04 that will give me all the package names that I have currently installed on my 10.04. Bring those names to 12.04 and tell apt to fetch the same softwares, but the versions of them that belong to 12.04. Install them.   Is there anyway to do the above steps or is there a totally different way in which I can achieve this?


Compare strings after getting substring JAVA

I'm having troubles comparing 2 strings after applying .substring() This is my example code: public class TestSubstring{  public static void main(String args[]){   String A = "BE359PH454128265";   String B = "EXAMPL_BE359PH4";   A = A.substring(0,8);   B = B.substring(7);   System.out.println("A = " + A);   System.out.println("B = " + B);  if(A != B){ System.out.println("Not Equal 1 "); }else{ System.out.println("Equal 1"); }  if(!A.equals(B)){ System.out.println("Not Equal 2 "); }else{ System.out.println("Equal 2"); }   } }  This is the output: A = BE359PH4 B = BE359PH4 Not Equal 1  Equal 2  Can someone explain we why "!=" doesn't work and "!A.equals(B)! does?


Find the value of $\lim_{x \to - \infty} \left( \sqrt{x^2 + 2x} - \sqrt{x^2 - 2x} \right)$

I am stuck on this.  I would like the algebraic explanation or trick(s) that shows that the equation below has limit of $-2$ (per the book). The wmaxima code of the equation below. $$ \lim_{x \to - \infty} \left( \sqrt{x^2 + 2x} - \sqrt{x^2 - 2x} \right) $$  I've tried factoring out an $x$ using the $\sqrt{x^2} = |x|$ trick.  That doesn't seem to work.  I get $1 - 1 = 0$ for the other factor meaning the limit is zero...but that's obviously not correct way to go about it :(  Thanks.


Biblatex not generating in-text citations or references

Sorry, title is vague as I don't know how to specify.  I am trying to use biblatex to produce a bibliography, but the references section is not produced, and all that is produced is a bold version of the reference name.  This is my MWE:  % !TEX TS-program = LuaLaTeX  %Macro Preamble \documentclass[11pt,a4paper]{article} \usepackage[utf8]{inputenc} \usepackage[english]{babel} \usepackage{fullpage}  \date{     \today}  \title{\vspace*{-9ex}\scshape %enter title here My cool title}       \author{\scshape\small\bfseries %enter name here Christopher Tatlock}  \usepackage[bibencoding=utf8,style=apa]{biblatex} \addbibresource{references.bib}    \begin{document} \maketitle   Hello, this is a reference \parencite{albert}  \printbibliography  \end{document}   The output for this is      Hello, this is a reference (albert)   This is my bib file:  @article{albert,   title={Understanding the Life Course through Newspaper Obituaries.},   author={Albert, Ajani Oludele and Anthony, Adegoke and Lateef, Adisa Ademola},   journal={Indian Journal of Gerontology},   volume={30},   number={4},   year={2016} }   It feels like I am missing something blatantly obvious.  I appreciate any help.  I am also trying with apacite with similar code, but apacite is generating      Hello, this is a reference (?, ?)   instead, with no references section.


What is the convergence speed of logistic sequence?

I am looking at the sequence $x_{n+1}=r\, x_n(1-x_n)$ where $r=1$. Let's choose $x_1=1/2$ so as to make the sequence convergent to 0. My question is: precisely how quickly does this sequence approach zero?  From my numerical experiments $\lim_{n\to\infty}n\,x_n=1$ seems likely. (That is $\mathrm O(1/n)$ convergence rate.) Do you have more precise result or some mathematical proof?


I manage to create a really nice beamer template and notes. I can create 2 pdfs: one with slides, one with notes. Now, I just need a dual screen pdf viewer that displays the slides in one screen and the notes in other screen and a timer. I need it for Mac.  Before mark as duplicated, I show off the collection of answers:        Does anyone know a better option for Mac? I don't find any acceptable solution :(   Keynote is, until now, the only acceptable but requires to copy the comments...


Sorry for wrong question formatting, but I'm new here and I don't know the way around these tools. I would like to know if there is a way to remove the chapter number from the document (preferably without any preamble lines). For example, if I have:  \chapter{chap1} \chapter{chap2}    \section{sec1}        \subsection{subsec1}   Then, sec1 has number 2.1 and subsec1 has number 2.1.1. I would like the "2" removed, so I have 1.1 for subsec1 and 1 for sec1 in this particular chapter.


If a sentence is based on speculation by the speaker and is formed like the following, "What if they killed my mom and dad" Would it follow like this? "What if they killed my mom and dad, then laid in wait and murdered me when I came home?" Is this the appropriate use of lie/laid?


Is it really possible to "boost" 6 V DC to above 50 kV? Or even 400 kV?

I am trying to create an arc generator and I have read about the marx generator but I am looking into more compact modules like the image below. All the ones I have found seem to be fake and actually supply less than 1/10th of what they are advertising.   Is there any reliable way of generating a (non-continuous) super high voltage arc?


Netherlands Schengen visa rejected; what can I do?

I applied to the Netherlands for a Schengen visa, and was refused. I showed hotel bookings for 14 days in the Netherlands, since I didn't have a confirmed itinerary when I applied.    The reason for refusal states:      Sufficient justification for the purpose and circumstances of the intended stay was not provided and the intention to leave the territory of member states cannot be ascertained.   I have two options now: appeal or apply from another country. As of now, I plan to spend the most days of the trip in Spain, so should I apply at the Spanish Embassy?   Would it be a problem, applying to Spain, after the refusal. My flight tickets are to and from Amsterdam, although most of the time would be in Spain.


Qualcomm Atheros AR8172 Driver fix? (lenovo g500s)

Recently I took a lenovo g500s laptop. the product id is LENOVO_MT_20245. after the installation, it could not recognize LAN network adapter. After googling I found out that it has a Qualcomm Atheros AR8172/8176/8178 PCI-E Fast Ethernet Controller  Command lspci -nn | grep 0200 says:  01:00.0 Ethernet controller [0200]: Qualcomm Atheros QCA8172 Fast Ethernet [1969:10a0] (rev 10)   Anybody know a way to fix this driver?


Finally, the Evaluation stage took place and did not take the full ten days that was projected.   Above is a sentence from a report I am preparing. I had originally written "were" but changed it to "was" after deciding that [full ten days] was a compound subject. It still doesn't feel right though, and I wonder if indeed both "was" and "were" are correct in this situation?  Could anyone please elaborate on this? Reference to sentence/phrase structure would also be appreciated.


SIM card in New Zealand with unlimited internet access

Are there any SIM cards with unlimited internet access available in New Zealand, for a stay period of 3 weeks?  Vodaphone counter at Auckland Airport don't offer any unlimited bundles, and I wonder if there are any available in Christchurch.


Credit score just tanked ~50 points and I'm not sure why

I check my credit score monthly using a credit tracking app provided by my credit card company. I use a reminder to check on the same day each month, and have been tracking my credit score for almost two years.  In the last year, the app switched from a TransUnion model to VantageScore 3.0. I have TransUnion data for the entire duration, but only about a year's worth of VantageScore data.  I have good credit, and my TransUnion score has increased steadily from ~740 to ~780 in the last two years.  My VantageScore started around ~760 and increased to ~800 last month. This morning when I checked my credit score, it had dropped just over 50 points to ~750.  My TransUnion score has stayed solid at ~780.  My questions are:  Should I be concerned about this sudden change in score?  Is there any way I can determine what changed to account for the sudden change in credit score?


All pages are being 404 cached on google? Currently we are using cloudflare, which I dont think is causing the problem, but you never know. Does anyone know how to understand the problem and what is causing this? I will be ready to provide further information for you to understand the issue aswell. Also, 1 year ago we switched from http to https. And last: If you take this URL  and change it to  then it will display a cached version correct ( added the "www" ) I dont know where to continue to solve this issue now. Edit SO I think I found out, if anyone are here with same issues, this might or I am sure its related to the new google MFI (Mobile First Index), since this has been enabled the error 404-cached version has been around, also google is saying this is the reason why alot of us are experiencing this issue. read more


Argument for the Smallest Division of Time?

Okay so a couple of months ago I was watch Vi Hart's video on how .999999... is equal to 1.  Some really interesting arguments that I had never heard before.  Yesterday, I came across an article on Planck time, and it got me thinking about where those two ideas might work together.   So ignoring that we already know about Planck time (and the other units), could we come up with an argument/proof showing that there must be a smallest, discrete unit of time using the same methods that we can use to prove that .99999... is equal to 1, only in reverse?  Yes, I've already googled this, but I could only fight people talking about the idea, not actually doing it.


ls command: What does the @ in file mode mean, and how to get rid of it?

After I download files on OSX and then want to use them, they often have an @ appended on the file mode whenever I do a ls -l. Here is an example output, see the @ near the beginning of the line:  ls -l *.php -rw-r--r--@ 1 username  staff  11179 Dec 17  2010 class.mysql.php -rw-r--r--@ 1 username  staff     24 Nov  1  2010 info.php -rw-r--r--@ 1 username  staff     61 Dec 23  2010 page.php -rw-r--r--@ 1 username  staff   1157 Dec 17  2010 photo.php   I think it is some kind of locking meganism, is that right? And how do I get rid of it?


Do journals allow authors to bring their own reviewers

Some papers are published under category "communicated by ...". Do this mean the author contact this person to review the paper instead of editorial board? My question is: do journals generally allow authors to bring their own reviewers for evaluating the papers? It seems that some journals allow that.


What do i do with the error "there are aliased coefficients in the model"

I was trying to test for multicollinearity using VIF. Here is my codes: mreg.mod = lm(price ~ bedrooms + bathrooms + sqft_living + sqft_lot +                floors + condition + grade + sqft_basement + sqft_above                + sqft_living15 + sqft_lot15 data = data) summary(mreg.mod) tidy(vif(mreg.mod))  But an error that says "there are aliased coefficients in the model" pops up. I was wondering if this has to do with my lm model?


What Is the Keyboard Shortcut for Sleep Display Without Eject Key?

I read that if you want to put your display into sleep the keyboard shortcut is Control ⌃+Shift ⇧+Eject ⏏, but what is it in Mountain Lion or Lion using a retina MacBook Pro or MacBook Air without an eject button?


Is the use of username/password in a mobile app needed?

We can log in with google or facebook. Android users should have google account already linked, ios users could create one. If someone doesn't want to use google, he can log in with facebook. Is the standard username (email) and password pair really needed?


Seeking title to a short SciFi story from the 50' or 60's

I am trying to learn the title of a short story that was about various races of beings on a ship heading to invade earth.  They feel smug and more advanced then the inhabitants of Earth.  However, their state of the arts weapon are something like muzzle loader. At the end of the story, much to the surprise of the aliens, when they land, they are made short work of by the machine guns and other weapons of Earth, that they had no experience with. Anyone have any insight to this title?


Blender is rendering all file formats with transpancy as boxes without the rest of the image

I followed this  to render fire. But, for some reason when I render the images, any image format with transparency just shows a box instead of the image. I can render the image with a background, but not without one. Any idea what would cause this, and how I can fix it? I'm using blender 2.92 by the way.  It should look like this, minus the background.  Edit: Here's the blender file:


Sometimes an answer () receives a number of comments of a similar nature and a sensible response is to edit the answer to account for the comments. If you just edit, the commenters get no notification and more than likely will never see the edit. Of course, it's possible to reply to each comment, "Hey @joe123 - see the edit" - which is OK for one comment, but not really more than that. It would be useful to have the option of notifying commenters about an edit. To be clear, the feature should be opt-in - it should default to notifying no-one. When you make an edit, there is list of commenters below who you can choose to notify. The commenters have already expressed an interest in the question, so it's not particularly spammy for them to receive a notification.


Prove that a function is a constant multiple of the other

Given $f$ and $g$ be entire functions and: $$|(f(z)| \leq |g(z)|$$ can you show me how to prove that $$f(z)=cg(z)$$ , where c is a (complex) constant? I have been able to prove this for the case $g(z) \neq 0$ by dividing $f$ into $g$: $$ \frac{|f|}{|g|} \leq 1 \rightarrow f(z)=cg(z) \text{by Liouville's theorem} $$ However, I don't know how to prove this result for the more general case in which $g(z)$ is arbitrary.


Should the functionality of Accept this Answer be changed?

A user asks a question to get an answer after a lot of research. They get the first answer, but it's not explained or detailed at all. As the asker did a lot of research on the question, he already understood the answer and therefore accepted that as the answer.  The user didn't get an answer anywhere else before, so this will be an important Q&A thread online.  Perhaps the questions without accepted answers may be the first priority for an answerer.  In the above situation, if the answer is not accepted quickly, then there may be more chance that the question will get more answers. So does the process of quickly accepting an answer degrade a thread?  If it is right, I'm suggesting a feature that an answered question gets more answers with the same importance shown to the OP.


Why do some packages have extra numbers before a colon on the front of their version string?

I have just noticed that Wine (and a number of other packages) have shifted their versioning scheme to something like:  1:1.6.2-0ubuntu3   I understand everything after the 1:... But what does the 1: refer to?  It doesn't seem to mirror the major version. Looking at a list of pending upgrades, there are versions like: 2:4.1.3... and there are plenty of packages without the #: prefix.  What's going on?


How to avoid a word to break in the last line of a paragraph

is any penalty value available to avoid a word break in a last line of a paragraph like below?


Can a Mac's airport card run 802.11 N, G, B or A only?

Occasionally it's nice to hard code a wired connection network port to not auto negotiate and force things to be 100 half duplex even though a higher speed is configured and negotiable on the switch.  Can I similarly force airport software and thus the hardware to only run one flavor of 802.11? Can I use the airport command to prefer a higher / lower channel rather than join by signal strength? Might alternative drivers be available or some developer testing tool to exert this level of control over the WiFi chipsets in Macs.  I want to force this on the mac end for cases where I can't control the base stations or want to test a specific channel of a simultaneous dual band router that is live with other traffic.  mac:bin mike$ airport --scan                             SSID BSSID             RSSI CHANNEL HT CC SECURITY (auth/unicast/group)                      na ala hele 00:26:36:9c:32:23 -59  2       Y  US WPA(PSK/TKIP/TKIP) WPA2(PSK/AES,TKIP/TKIP)                       na ala hele 00:26:bb:79:23:1f -59  2       Y  US WPA(PSK/TKIP/TKIP) WPA2(PSK/AES,TKIP/TKIP)                  fast na ala hele 00:26:bb:79:23:20 -74  149,+1  Y  US WPA(PSK/TKIP/TKIP) WPA2(PSK/AES,TKIP/TKIP)  mac:bin mike$ airport --getinfo      agrCtlRSSI: -75      agrExtRSSI: 0     agrCtlNoise: -86     agrExtNoise: 0           state: running         op mode: station       lastTxRate: 81         maxRate: 300 lastAssocStatus: 0     802.11 auth: open       link auth: wpa2-psk           BSSID: 00:26:bb:79:23:20            SSID: fast na ala hele             MCS: 4         channel: 149,1 mac:bin mike$ ls -l /usr/local/bin/airport  lrwxr-xr-x  1 root  wheel  89 Sep 13 11:40 /usr/local/bin/airport -> /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport


Limit of $x \log x$ as $x$ tends to $0^+$

Why is the limit of $x \log x$ as $x$ tends to $0^+$, $0$?   The limit of $x$ as $x$ tends to $0$ is $0$. The limit of $\log x$ as $x$ tends to $0^+$ is $-\infty$. The limit of products is the product of each limit, provided each limit exists. Therefore, the limit of $x \log x$ as $x$ tends to $0^+$ should be $0 \times (-\infty)$, which is undefined and not $0$.


$g\in G$ maximal order in $G$ abelian then $G=\left\oplus H$

If $g\in G$ is an element of maximal order in a finite abelian group $G$ then exists $H\leq G$ such that $G=\left<g\right>\oplus H$  Attempt: Using fundamental theorem I know that $G=C_{n_1}\times\cdots\times C_{n_k}$ where $n_i|n_{i+1}$. With some work I proved $|\left<g\right>|=n_k$, so $C_{n_k}\cong \left<g\right>$. Then $G\cong H\times \left<g\right>$, but this is not an equality.


I would like to update to iOS 9.2.1 on my iPhone 4, which is currently running iOS 7.1.2. Is this possible?


Is use of "such as" in the following sentences correct grammatically and conceptually?     The secondary flow loss is due to interaction between vortices and   boundary layer of suction and hub surfaces, such as tip leakage and   hose-shoe vortices, in Wells turbine.


Are these two sentences same?     With the exception of Rob and me, everyone in the class finished   the assignment before the teacher came.      With the exception of Rob and me, everyone in the class had   finished the assignment before the teacher came.   On searching, I found that "had finished" is the correct usage. Is it because it is followed by "before the teacher came"?  If I remove the "before the teacher came" from the first sentence, to make it-     With the exception of Rob and me, everyone in the class finished the   assignment.   will it be (grammatically) correct?


Contact Data Decision Split for synchronized Salesforce DE leads to wrong path

I encountered a problem in Journey Builder, where decision splits that check for changes in Salesforce Service Cloud (filter expression is configured to retrieve Contact Data from synchronized data extension) don't lead to the path they should. The data is definitely synced correctly, as retrieving the changed data from the synchronized data extension via AMPscript in a mail sent by the journey leads to the correct result (retrieving the data using the salesforce-id of the object that is present in event/journey data).  This problem occurs every time a contact enters the journey more than once (which is legitimate as there can be more than one trigger object per contact (in my use case these objects represent offers for a customer)) and decision splits should act on changes in service cloud. However this shouldn't be a problem as the changed record can be uniquely identified by a salesforce id and even the journey is triggered by this very service cloud custom object (Salesforce Data Event).  Summary:   Salesforce Data event triggers the journey (update of custom object X) The contact has a 1-to-many relationship to custom object X Salesforce Contact-Id is used as subscriber key Waiting steps in journey are long enough for synchronization to definitely happen Data is synchronized correctly and can be retrieved via AMPscript Contact Data decision split doesn't evaluate correctly


I came across  today that instead of having [closed], it had [on hold]. What is this new change, and what does it affect?


Is there a version of \include and \input for bibtex?

I'd like to spread out my references between multiple bibtex files. I tried putting all my references into a file called etho.bib, then put \input{etho.bib} into my main bibtex file. This didn't word. I also tried using \include instead of \input and etho.tex instead of etho.bib, but none of that work.  Is there some way for the bibtex compiler to include text from another document into your .bib file?


Quadratic residues and index w.r.t. primitive root of a odd prime p

I have a problem in solving my number theory homework. My question is as follows:  Let $p$ be an odd prime. Prove that $a$ is a quadratic residue mod $p$ if and only if the $I_{g}(x)$ (index with respect to any primitive root of $p$) is even.  Please edit my writing. Thanks. Does anyone know where to start? Thank you very much for everything!


Feasibility of a neural network fitting a specific multivariate quadratic function?

I have run into some problems when trying to train a network that fits some multivariate quadratic function, or the Euclidean distance between 2 points in a 3-dimensional space, where they are 'pretty far from each other'(typically between $2.1\times10^7$ and $2.4\times10^7$).  To begin with, I have a whole bunch of data from a simulation that features the coordinates of both points, and the distance between them calculated with exactly the same formula as what I attempt to fit, stated as below:  $d=\sqrt{\Delta x^2+\Delta y^2+\Delta z^2}$.  The input data are a set of 3 decimals of the difference of coordinates of both points, one really close to the origin point and another faraway. (Originally 6 when I didn't do the subtraction myself.) The set is generated by a simulation with numpy.random(size = 3) and then scaled up with a proper multiplier.    and with Keras I constructed something like this:  train_f, test_f, train_t, test_t = train_test_split(X_dist, Y_dist, test_size = 0.3) nn_r = Sequential() nn_r.add(InputLayer(input_shape = (train_f.shape[1], ))) nn_r.add(Dense(6, activation = 'linear')) nn_r.add(Dense(12, activation = LeakyReLU())) nn_r.add(Dense(12, activation = LeakyReLU())) nn_r.add(Dense(1, activation = 'linear')) nn_r.compile(loss = 'mse', optimizer = Adam(), metrics = ['mae', 'mse']) es_r = EarlyStopping(monitor = 'loss', patience = 30) lr_r = ReduceLROnPlateau(monitor = 'loss') nn_r.fit(train_f, train_t, epochs = ep, verbose = 1, callbacks = [es_r, lr_r]) score_r = nn_r.evaluate(x = test_f, y = test_t)   The network does accept the design and starts well, but never giving a reasonable result; mse reaches somewhere above $1\times10^9$ in the end.  I have tried normalizing the input with sklearn.preprocessing, which did accelerate the training process but did not help with the accuracy; modifying its structure did affect the result significantly but it never end up in an acceptable result either. I even tried doing the subtraction myself and feed the network with the difference, and that did not work either.  Additionally, the system might need to deal with noisy data so I decided to give NNs a try instead of simply putting some numbers back in the formula above.  I'm not sure where the problem could be from, and how I can make it work better. Thank you in advance.


I have 23 reputation points, but I cannot chat

On superuser.com I have 23 reputation points. However, I get a message saying that I need 20 reputation points to chat. The chat room is Super User -> .


Showing arrowheads in line end using QGIS?

I would like to show arrowheads in the endings of every drawn linestring.  Is it possible in QGIS?    I have been trying to use a marker line but repeats all de arroheads all over the line, it is not restricted to the ends:


How to store international phone numbers in PostgreSQL?

What is the correct way to store phone number data after applying a new mask for user input (example for UK; 44 07400 123456) if the type of the existing column is character varying(32)? Does storing it as it is generated by mask has a drawbacks (especially space characters)?   In other words, what are some pros and cons of storing it as formatted or unformatted might be better to asking for my case, since I'm not dealing with the type of the column and I'm going to stay with the same type. Especially, what I'm really care about is that is, what would be best practice? +4407400123456 or 44 07400 123456 (with spaces).


If we have the set A with $\#A=5$, how much graphs can be made over   A?   The solution says $2^{5^2}$, that is exactly the same number of binary relations on A. I initially thought that the solution would be: $2^\binom 52$, but i was worng.   Any tip about counting graphs would be appreciated.


This is a little bit off topic as it is not exactly related to TeX.  I saw recently that  was updated to 1.020 which comes with math table support.  Does any one had a chance to play with this font and use it with unicode-math, and in particular with the LuaTeX engine?  I am very interested in purchasing a complete set of this nice fonts family. However I am concerned about its usability with the unicode-math package. Unlike Cambria Math or XITS Math, Minion Math does not come with a single font, instead it has 20 (4 weights 5 optical sizes) fonts. So it will be better to know how it works before spending 700 euro.  In particular, say the following minimal document, will it use correct optical size of the fonts for each of the three formulas? I had trouble with using correct optical size of Minion Pro fonts with fontspec. I worked it out with the SizeFeatures and OpticalSize. However, I am not so sure if the same strategy will work for Minion Math with unicode-math. In addition, in Cambria Math, etc., the bold symbols and alphabets are chosen directly from the unicode math enabled fonts. But in Minion Math, from the glyph tables on their websites, there seems no bold alphabets in each font. So will the mathbf in the document below work out of box?  \documentclass{article} \usepackage{fontspec} \setmainfont{Minion Pro} \usepackage{unicode-math} \setmathfont{Minion Math} % or what ever fonts name actually is  \begin{document} \fontsize{5}{5}\selectfont \[ \mathbf{E} = mc^2 \] \fontsize{10}{10}\selectfont \[ \mathbf{E} = mc^2 \] \fontsize{36}{36}\selectfont \[ \mathbf{E} = mc^2 \] \end{document}


Is it possible yet to synchronise music to an iPhone running iOS 5/6?  I tried it in the  (Quantal Quetzal) live environment, but I didn't have any luck with  or .  Is there some way to do it?


I just came over this syntax in some of the questions in this forum, but Google and any other searchengine tends to block out anything but letters and number in the search so it is impossible to search out "=>".  So can anyone tell me what it is and how it is used?


I have Ubuntu 16.10 (although the same happened on 16.04) on a dual boot with Windows 10. I noticed some time ago that my kern.log file was getting pretty big (10GB or more) so I decided to check it. The same error seems to be repeating every second or less:  Dec 19 17:31:01 andrew kernel: [   99.027473] pcieport 0000:00:1c.5: PCIe Bus Error: severity=Corrected, type=Physical Layer, id=00e5(Receiver ID) Dec 19 17:31:01 andrew kernel: [   99.027474] pcieport 0000:00:1c.5:   device [8086:9d15] error status/mask=00000001/00002000 Dec 19 17:31:01 andrew kernel: [   99.027475] pcieport 0000:00:1c.5:    [ 0] Receiver Error         Dec 19 17:31:01 andrew kernel: [   99.027479] pcieport 0000:00:1c.5: AER: Corrected error received: id=00e5 Dec 19 17:31:01 andrew kernel: [   99.027826] pcieport 0000:00:1c.5: can't find device of ID00e5 Dec 19 17:31:01 andrew kernel: [   99.027887] pcieport 0000:00:1c.5: AER: Multiple Corrected error received: id=00e5   I have tried adding to the grub pci=nomsi and pci=noaer but it keeps popping up. I am using a ASUS Laptop with an Nvidia Geforce 920M. Maybe that's the reason?


So I updated my laptop from Ubuntu 18.04 to 20.10 and since then I've been having trouble executing the command sudo apt-get update  Please help me out! Thanking you.  Some errors are as follows:  E: The repository 'cdrom://Ubuntu 18.04.3 LTS _Bionic Beaver_ - Release amd64 (20190805) 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. E: Failed to fetch http://linux.teamviewer.com/deb/dists/development/InRelease  403  Forbidden [IP: 2600:9000:21f6:a800:1c:3aaa:b100:93a1 80] E: The repository 'http://linux.teamviewer.com/deb development InRelease' is not signed. 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. E: The repository 'http://ppa.launchpad.net/octave/stable/ubuntu focal 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.   The output for cat /etc/apt/sources.list is :    Thanking you once again. :)


I am new to Linux and I'm trying Ubuntu 20.04.1 on a USB key to see what it's like. I wanted to watch a movie on Prime Video using Firefox, but I couldn't : it asked me to allow DRM, which I did. But still, I wasn't able to watch my movie (says an error occured) and I tried on Netflix (error F7355): issue is the same. I have been looking on the internet for a solution but I couldn't find any. I have :  Updated Firefox using sudo apt install --only-upgrade firefox Changed media.libavcodec.allow-obsolete;false to true in Firefox about:config Checked that I have OpenH264 and Widevine plugins activated Tried commands I found online... Such as sudo apt-get install libavcodec-extra, sudo apt-get update && apt-cache search libavcodec-extra, sudo apt-cache search libav | grep extra- or sudo apt-cache search libav | grep extra-...  Most of the posts I found were pretty old. It seems like i'm missing this "libavcodec" but I don't really know what it is nor how I should get it. I can play YouTube videos, however Twitch videos do not work (Error 4000) Could anyone help me ? I was happy with my Linux experience so far, but I'm a bit disapointed that it's so hard to do something as simple as watching a stream ! Thanks a lot and sorry for my english, I'm not a native speaker.


Only allow plugin to be activated on root site of multisite

I'm developing the  plugin.  Its purpose is to scan for altered files and it works fine for a single installation of WP. But when you look at multi-site it's not something that wants to be enabled on all sub sites, as they all share the same files and (to be honest) only a network admin should be the one that wants to be notified against file changes.  So my question is this:      How would I program it, to only be allowed to be installed/run from the root site of a multi-site installation? So: that means not allowing it to be network installed and only activated from the root blog.   Anyone know of any ways on how I could achieve this?


How far away must a galaxy be for its light never to reach us due to the expansion of the universe?

My understanding is that at the present rate of expansion of the universe some galaxies are growing more distant from us at such a rate that light from them will never reach us. My question is how far away a galaxy must be for this to be true of it.


I want to check if a string ends with  - v{number}   So for example  hello world           false hello world - v2      true hello world - v       false hello world - v88     true   Not entirely sure how to go about doing this RegEx.  var str = 'hello world - v1'; var patt = new RegExp("/^ - v\d*$/"); var res = patt.test(str); console.log(res);   How could I fix the above RegEx?


Please someone who specializes as a grammarian answer this: The family is/are pursuing their individual interests.  Could you also give me the authoritative source for the answer!!!


When (and more importantly, why) does $AA^T$ have an inverse?

Say I have a matrix A that is m by n and m < n. For context, say I am interested in finding a vector $ \theta_z \in \mathbb{R}^m$ such that:  $$ A^T \theta_z = \theta_x$$  i.e. we have more rows/"equations" than columns/"unknowns".  I was going to do it by multiplying both sides by A and then find the inverse of $AA^T$.  I was told that this only works when we have linearly independent rows. Is this suppose to be obvious? What is an intuitive way to explain this? Also, I am even more interested in a precise and rigorous proof if there is one.   I was also told that when the rows are dependent, then  the system has an infinite number of solutions. However, I was a little skeptical about this, because if we have more rows, then if we did some elimination on the original $ A^T \theta_z = \theta_x$, then we could have at most a rank of size $m$ (one for each column). Which could lead to only 1 solution or zero (none) but never to infinity. So I think that solutions is wrong, i.e. linearly independent rows if anything, shouldn't lead to more than 2 solutions ever, we should only have 1 or zero for the original system $ A^T \theta_z = \theta_x$. Is that correct?


So I've been trying to prove that there's no simple group of order $300$. This is what I did and I was wondering if it was enough.   $|G|=2^2 \cdot 3 \cdot 5^2$. Suppose $G$ is simple. Then there would be $6$ Sylow $5$-subgroups, one of which will have an index of $6$. But then $|G|=300$ does not divide $6!$ which leads to a contradiction. So, the number of Sylow $5$-subgroups is $1$ and $\exists$ a proper normal Sylow $5$-subgroup in $G$. Hence $G$ is not simple.


Assume that A and B are two systems. For example A consumes 3unit and B consumes 4unit of the energy. Now we know to A saves 0.25% in energy consumption than B.I want to draw a diagram and want to type on the y axis. I would like to which of these is correct:        . . . the energy saving ratio of A to B . . .    . . . the energy saving ratio of A than B . . .    . . . the energy savings ratio of A to B . . .    . . . the energy savings ratio of A than B . . .    . . .. or?


How to punctuate "eight- or nine-year-old"

Suppose I want to say "eight-year-old or nine-year-old" more concisely. Where would I put dashes? Should it be: "eight or nine-year-old" "eight- or nine-year-old"


A friend of mine tried to download a file, but it was cut off mid-download and she got stuck with a .rar file that has 0 bytes, but in the details it says 8MB. Pressing Delete doesn't do anything. Cmd can't find the file.      It says 8MB in the Details, but this won't let me post more than 2 images.


Why use an int as a lookup table's primary key?

I want to know why I should use an int as a lookup table's primary key instead of just using the lookup value as the primary key (which in most cases would be a string).  I understand that using a nvarchar(50) rather than an int would use way more space if it is linked to a table with many records.  On the other hand, using the lookup value directly would basically save us doing a join. I can imagine this would be a big saving if the join is always required (We're working on a web app so this counts quite a bit).  What are the advantages of using a int primary key (specifically for a lookup table) other than it being "the standard thing to do"?


My spelling tool suggests that I should fix "All of the" to "All the" in the following statements:   If we take all of the above notes into account... All of the methods described above shorten your path to... Next step will be just to execute all of the statements above... ...but there is no single answer to all of them.   What would be the correct variant?


Parent method with the proper data type is not getting invoked, if called from Child instance

Code:          class Program {     class A     {         public void abc(int x)         {             Console.WriteLine("abc from A");         }     }     class B : A     {         public void abc(double x)         {             Console.WriteLine("abc from B");         }     }     static void Main(string[] args)     {         B b = new B();         b.abc(100);         Console.ReadLine();     } }   On calling abc() method from class B instance,  eventhough we are passing integer data ie 100 as an argument still why the execution of the program goes with method parameter that is defined with double? Please note that there is a method already defined for integer in the parent class.   Why the output of the above program is "abc from B" rather than "abc from A". Kindly advise.


Where is the Ubuntu console on Windows10?

I updated my Windows 10 system to the 1607 "Anniversary Update" version and I can't find the Ubuntu Bash console.  So... Where is it?


Prove the statement for definite integral

We have positive continuous function $f(x)$ defined on $\mathbb{R}$, such as $\int_{-\infty}^{+\infty} f(x) dx = 1$ let $\alpha \in (0,1)$ and $[a,b]$ is an interval  of minimal length amongst intervals for those holds: $\int_{a}^{b} f(x) dx = \alpha$. Task is to prove that $f(a) = f(b)$.    I managed to sum up following statements: $F(\infty) - F(-\infty) = 1$ $F(b) - F(a) = \alpha$ And one to prove is: $f(b) - f(a) = 0$ I am looking for hints to build a proof here.


Using a comma after "but" as done on W4 form

The sentence is found on line C, where it says...     But, you may choose to enter “-0-” if you are married and have either a working spouse or more than one job.   Is that correct? And why? Seems rather odd that the government would make such a mistake, no?  Edit - I'm not asking if it's correct or not to put a comma after a conjunction. I'm asking if it's OK to use "But" as a substitute for "However." I'm also not asking if it's "always necessary" to put a comma after conjunctive adverbs like "however." I'm saying this because it's the government that wrote it, and the government, I'd think, would be right in doing so. I just wanted to know if it's "generally" acceptable to do that or if it's an actual mistake.


I'm ready to migrate to Ubuntu but when I went to the download section I read "The latest version of the Ubuntu operating system for desktop PCs and laptops, Ubuntu 15.04 comes with nine months of security and maintenance updates" What that means? Is this a trial version? why only 9 months?  Like I said in the beginning of my post I'm ready to migrate, but not if it's only for 9 months.  I apologise in advance if this is a stupid question or it's obvious for you, but I don't know anything about ubuntu, so I'd be glad if somebody could clarify that for me.


Show $A\setminus (A\cap B)=(A\cup B)\setminus B$

I'm having problems with this; the strategy is to show the left side is in the right side, and vice versa. Thus far I can only show that both sides of the equality are in A\B. Can I use "the empty set = A and not A" as a fact? Because then it works. Or just show me how to do it!


Most elegant way to force a TEXTAREA element to line-wrap, *regardless* of whitespace

Html Textarea elements only wrap when they reach a space or tab character. This is fine, until the user types a looooooooooooooooooooooong enough word. I'm looking for a way to strictly enforce line breaks (eg.: even if it results in "loooooooooooo \n ooooooooooong").    The best I've found is to add a zero-width unicode space after every letter, but this breaks copy and paste operations. Anyone know of a better way?  Note: I'm referring to the "textarea" element here (i.e.: the one that behaves similarly to a text input) - not just a plain old block of text.


Compilation warning when I create a LinkedList in Java

When creating a LinkedList with this statement in Java  LinkedList<Integer> adj[] = new LinkedList[numPlaces()];  I get two warnings saying   RoadMap.java:247: warning: [rawtypes] found raw type: LinkedList                         LinkedList<Integer> adj[] = new LinkedList[numPlaces()];                                                         ^   missing type arguments for generic class LinkedList<E>   where E is a type-variable:     E extends Object declared in class LinkedList RoadMap.java:247: warning: [unchecked] unchecked conversion                         LinkedList<Integer> adj[] = new LinkedList[numPlaces()];                                                     ^   required: LinkedList<Integer>[]   found:    LinkedList[] 2 warnings   The code runs the way it is inteded to but what do I need to change to solve them?


How to maintain OpenStreetMap labels/details (from QuickMapServices) when exporting from QGIS?

My question is about OpenStreetMap place labels in QGIS, and how to keep them at a similar size when exported to as they appear in the software. I realise variations of this question have been asked before and it used to be an issue with the OpenLayers plugin but I have yet to find a workable solution.  I am having issues with losing the scale of labels of my backdrop mapping when exporting my QGIS print template to a PDF. I need the labels to maintain their size seen in both the map view (screenshot 1) and print template (screenshot 2). However when I export, the labels shrink to a unusable size (screenshot 3).         Does anyone know a work around to this issue?   I have found you can lower the DPI in the print template export setting which produces larger labels, however this also lowers the resolution of the map to a near unusable level.     Someone had similar problems:   However I have tried this solution (screenshot 4) and unfortunately I don't see any change in the label size to the output? (screenshot 5)      I am not sure if I am putting in this new parameter the URL correctly or not?


Travelling from Mumbai to Amsterdam, with a transit in France. Can I shop duty free in Mumbai?

Normally, I wouldn't consider shopping Duty Free with a transit flight. But since this transit is within the EU, I wonder if it might be possible to carry some alcohol from the Mumbai Duty-Free. Your perspectives will be much appreciated.  Thanks!


Where should I ask a question about a wireless printer?

I have a new printer that I'm trying to hook up to my network, and wanted to ask for help. I looked through all the sites and none of them seemed to be right for my question. Which site should I use? Does such a site even exist?


Compact Hausdorf space $\implies$ not the countable union of nowhere dense sets?

I can sort of see this intuitively, seeing as it's a similar argument to the Baire Category theorem, but does anyone have a proof I could look at?   Would it suffice to say that every locally compact Hausdorff space is also a Baire space $\implies$ not the countable union of nowhere dense sets?  If so, how about this for a proof?     Since X is locally compact Hausdorff, it is    homeomorphic to an open subspace of a compact   Hausdorff space, say Y. By the Baire Category    Theorem, Y being a compact Hausdorff space   implies that Y is a Baire space. Since    open subspaces of Baire spaces are Baire spaces   Then X is a Baire Space.   This is under the assumption that a Baire space $\implies$ not the countable union of nowhere dense sets? Unless I misinterpreted the Baire Category Theorem.


Python substring has what defaults for x,y when z is negative? (this has nothing to do with x,y being negative)

For a Python substring, I'm confused on defaults of x,y when z is negative Next lines: the defaults for x:y are no problem understanding because z is positive alpha = "abcdef" print(alpha[0:6:1])  #abcdef print(alpha[::1])      #abcdef    defaults for x,y change this to [0:6:1]  But when change to a negative z I'm confused. I would think [::z] becomes [0:6:z] regardless of z being +1 or -1. But seems defaults for x,y are different when the z is pos or neg print(alpha[0:6:-1])   # (no defaults example) prints nothing - OK print(alpha[::1])      # abcdef    default [::1] becomes [0:6:1] - OK print(alpha[::-1])     # fedcba    default [::-1] not becomes [0:6:-1] - why different x,y defaults?  Response to suggested duplicate I don't think this is a duplicate - the other question is about negative x,y. This questions is about x,y defaults when z is negative. This question involves a double colon syntax - that does not appear in the "duplicate question" reference.


Which number is more near to $S$? $S=\frac{(2^3-1)(3^3-1)\dots (100^3-1)}{(2^3+1)(3^3+1)\dots (100^3+1)}$  1.$0.6$ 2.$0.67$ 3.$0.667$ 4.$0.6667$  I personaly can not do anything special I have tried to calculate some easy case but no resaults any hints?


What is a good book to learn number theory?

What would be a good book to learn basic number theory? If possible a book which also has a collection of practice problems? Thanks.


Which is preferable, simple past or present perfect, in situations like this one: I had a conversation with my friend and we planned to do something; shortly afterwards I call him back to announce the accomplishments. My biggest doubt about simple past is that perfect aspect is used to indicate past action (accomplishment) with current relevance, at the same time I'm not sure if I'm allowed to use present perfect, because there's a gap between accomplishing and the current moment, which is a characteristic of simple past.


is there any diffrence to use nonlinear or liner activation function in single hidden layer network

I am working in a classification problem in which I use RBF with a single hidden layer. I want to use SoftMax activation function for the output layer. I already read some documents about the activation function of the output layer but can't find my answer. I try to write the equation for softmax and linear activation function and compare them. in my opinion yes they are different, but after I saw some documents I become confused so to become sure about I decide to ask it here.   is there any difference between linear and nonlinear activation function in a single hidden network?


Make "recovery mode" write to files when file system is read-only?

I am trying to install Nvidia Driver 384.59. in 16.04 LTS. I bought a Nvidia 1050TI graphics card, which works in Windows 10,  but Ubuntu can't start a UI. -  or rather it tries - I see the GUI login prompt for a second or two, hear a "clunk" on my speakers, and the screen clears to black with a blinking cursor, (no prompt) in the upper left corner.  It will give me the recovery boot menu, and then a text box that I'm in low graphics mode.  after that all choices seem to lead to the "flash of a GUI"- CLUNK- black screen.   I have tried to use "drop to root prompt", but the file system is read only, so I can't use apt to upgrade my drivers.


I answered this question on StackOverflow:  Then a bounty of +50 is offered on this question. As the question is changed by the owner, I change my answer in accordance with the changed question. I changed my answer 13 times. It shows this:    community wiki 13 revs swemon  After the bounty period, the owner accepts my answer. As far as I know, when one's answer is accepted, one gains +15 reputation. But my reputation has not changed.


I changed my Blender Units to Metric System, but when I'm building things, my meshes are transparent, i.e. I can see through faces like in wireframe even though my wireframe is turned off. All faces have a light white in non-wireframe mode, but I can still see through them.   How do I reverse this?  Another issue I get is this    Looks like clipping is not working properly.


Proof that $d^2 \phi = 2\pi \delta^{(2)}(r)dx\wedge dy$ in polar coordinates around a puncture?

In the literature on point particles in 2+1 gravity, I often see the identity  $$d^2 \phi = 2\pi \delta^{(2)}(r)dx\wedge dy$$  being used. Here, the particle is a puncture located at the origin and $(r,\phi)$ are polar coordinates around this puncture.  One example is in  (unfortunately it's behind a paywall), where in equation 3.4 the author uses the above identity to show that the torsion and curvature are both described by delta distributions. For example, for the curvature, since the connection is given in equation 3.3b by $\omega=M d\phi$, the curvature is  $$F=d\omega=Md^2\phi=2\pi M \delta^{(2)}(r)dx\wedge dy.$$  Other papers seem to be using this result as well, and cite the above paper. One example is , equations 4.6-4.7.  I know that $d^2$ is supposed to be always zero because the partial derivatives commute, so this has to fail somehow for the identity to be satisfied, but I don't know how that would happen in this case.


Why when using Mathf Lerp the speed is not changing according to Time.deltatime?

using System.Collections; using System.Collections.Generic; using UnityEngine;  public class DetectCollision : MonoBehaviour {     public Transform player;     public Transform target;     public bool turnOnOffPlayerAnimator = false;      float timeElapsed = 0;     float lerpDuration = 3;     float startValue = 1;     float endValue = 0;     float valueToLerp = 0;      private Animator playerAnimator;     private bool entered = false;     private bool prevFacing = false;     private Rigidbody rigidbody;     private bool stopped = false;      // Start is called before the first frame update     void Start()     {         rigidbody = player.GetComponent<Rigidbody>();          playerAnimator = player.GetComponent<Animator>();          if (turnOnOffPlayerAnimator)             playerAnimator.enabled = false;     }      // Update is called once per frame     void Update()     {         var currFacing = IsFacing(target);         if (currFacing != prevFacing)         {             // here you switched from facing to not facing or vise verca.             timeElapsed = 0;         }         prevFacing = currFacing;          var distance = Vector3.Distance(player.position, target.position);          if (IsFacing(target))         {             if (entered && distance > 30)             {                 if (timeElapsed < lerpDuration)                 {                     valueToLerp = Mathf.Lerp(startValue, endValue, timeElapsed / lerpDuration);                     playerAnimator.SetFloat("Forward", valueToLerp);                     timeElapsed += Time.deltaTime;                 }                 playerAnimator.SetFloat("Forward", valueToLerp);                  valueToLerp = 0;             }         }         else         {             if (valueToLerp < 0.9f)             {                  if (timeElapsed < lerpDuration)                 {                     valueToLerp = Mathf.Lerp(endValue, startValue, timeElapsed / lerpDuration);                     playerAnimator.SetFloat("Forward", valueToLerp);                     timeElapsed += Time.deltaTime;                 }                 playerAnimator.SetFloat("Forward", valueToLerp);             }              Mathf.Lerp(valueToLerp, 0, Time.deltaTime * 0.0001f);         }          if(turnOnOffPlayerAnimator)         {             playerAnimator.enabled = false;         }         else         {             playerAnimator.enabled = true;         }     }      private void OnTriggerEnter(Collider other)     {         entered = true;          Debug.Log("Entered !");     }      private void OnTriggerExit(Collider other)     {         entered = false;          Debug.Log("Exited !");     }      private bool IsFacing(Transform target)     {         Vector3 forward = player.TransformDirection(Vector3.forward);         Vector3 toTarget = target.position - player.position;         return Vector3.Dot(forward, toTarget) > 0;     } }  I tried first 0.1f but it didn't change the lerp speed. I want that if the player is pressing the W key and moving the player forward and then stop pressing the key W it will smooth slow will lerp to 0. and it does but I also wanted to control the lerp speed. I want that when the player is starting moving backward direction if the player leave the W key the player should stop slowly to 0. This should be the line : Mathf.Lerp(valueToLerp, 0, Time.deltaTime * 0.0001f);  but the Time.deltaTime does not seems to affect the lerp at all. the lerp is working fine I just wanted to control the lerping speed too.


I am planning a 10-day visit to France and Spain. We will be visiting Paris first and then Barcelona and then Madrid.  Which country should we apply for the visa? Our entry point is Paris and we are planning to stay 6 days in Spain.


I wanted to ask a question about my forum. I wanted to know if a repeated question is asked daily over the course of a year with multiple users asking the same thing or answering the same thing. For example “yes, it would be healthy to eat vegetables daily.” If this has been said 50 times on my forum would it be considered duplicate content ?   Can multiple users sign up and post repeated questions through the year pertaining to the same topic. For example “how much water should I drink?”


Example of non-trivial set that is both closed and open in $\Bbb R$?

I need a very simple example of a set of Real numbers ( if there is any ) that is both closed and open on R .and the boundary of it equal empty set and it is neither empty set nor R.  like , The boundary of a set is empty if and only if the set is both closed and open (that is, a clopen set). on    to disprove this statement ,Let (X,T ) be a topological space and let A ⊆ X. If Bd(A) = ∅, then A = ∅ or A = X.


Normed space where all absolutely convergent series converge is Banach

Let $A$ be a normed space where every absolutely convergent series converges in $A$.     How do I prove that $A$ is Banach?   Let $\sum_{n=1}^\infty x_n$ be an absolutely convergent series in $A$, then we know that $\sum_{n=1}^\infty ||x_n||$ is convergent in $\mathbb{R}$ and that $\sum_{n=1}^\infty x_n$ is convergent in $A$. Now using this, we want to show that all Cauchy sequences $\{x_n\}$ in $A$ converge. How would I do this?


How to make DNS server propagate faster if you are a site owner?

It's often the case that I want to change name servers because my site is messed up.  Well, it takes a very long time for the name server to propagate.  Is there something in DNS, or registrar or anything I can do to speed that up.  Flushing my dns server using  and it rarely works


3 days im working on regular expressions and something got stuck in my head here is the thing; i want my regex to accept like this one  0 123 456 78 90  0355 369 5878  01234567890  last one is easy to do, like   "(0[0-9]);   but i dont know the rest on java


Internal GPS interfering with mock locations?

I've been using mock locations in my latest endeavors, and I'm having some issues. I enabled a mock location app from the developer options, set my Location Mode to 'Device Only,' and took precautions such as moving the app to System.  Everything is working how I intended it, except my location keeps bouncing between the mock location and my actual location. I've tried desperately to prevent my internal GPS from interfering with the mocked location, but with no luck.   The only method that I managed to have success with was by wrapping aluminum foil around my phone to inhibit the GPS.. this works but it's very inconvenient. I'd be grateful to anyone who can shine light on my troubles.  I'm running rooted Android 6.01 (Marshmallow) with a OnePlus Two device if it matters. I've tried different mock location apps with similar results on them all.


What utility can move my Windows boot partition over to another hard drive?

Can anyone recommend a cheap/free utility that can do this without very much effort?  My preference is that it would be really easy.    Boot into Windows Pick drive to move Pick target drive It copies everything over, and reboots to the correct partition.


I am running a lasso model to predict a continuous variable, and I have continuous and categorical inputs.  In terms of centering and scaling - is it correct that this should only be applied to continuous variables? Also, in terms of the dummy variables step, can this be ignored for the categorical? It just doesn't make sense when it comes to scoring.  For example, if the training set has a category called Cats, that has levels A-Z, this would create a column for A-Z. But if my scoring set is missing one of these levels then it will fall over. Looking for some guidance.


Amazon S3 Console: How to find total number of files with in a folder?

So I can see S3 console and can get into my folder with files listing but I don't find way to find total number of files in it other than going thru pagination which does not work considering thousands of files.


Explain why $| e^{iwx} - 1 | \le 2 |w| \, |x|$

A paper stated $| e^{iwx} - 1 | \le 2 |w| \, |x|$ without any further explanation. I struggle to find an explanation because Euler's formula doesn't help.   Can you give me a give why this statement might be true?


Policy on accepting answer after question is no longer relevant to original poster

Let's say I have a problem, and post a question on StackOverflow.  I don't get any good answers, so I end up writing my own buggy implementation, or shelving the feature entirely.  Months later, someone provides an answer.  It looks promising and gets a few upvotes, but by this point it is too late to rip out the old implementation, or I have left the job, etc.  The question is no longer relevant to me.  Do I have a responsibility as the original poster to see if this answer would have solved my problem?  Relatedly, if someone pesters me about my accept rate, is "I no longer have the ability to check if any of these answers are right" an acceptable response?


Is there a glossary for all the acronyms of Stack Exchange sites?

Maybe this question is a duplicate, but I'm not finding it in my searches.  There are several acronyms in several websites, such as: MMA, MWE, ...  I visit several sites, but as I visit some of these sites infrequently, I do not know what some people are commenting on.  Is there a glossary of this in the Help Center?


Find out which filters were applied to an email in Gmail

I've got about 20-30 filters set up in my work Gmail account doing a range of things, from filtering newsletters that won’t let me unsubscribe into the bin, to marking messages that come through a web form and putting them in a separate folder etc.   One of the filters is acting odd because when I reply to some emails, instead of the response ending up in the sent for some reason it’s getting moved into my inbox—so that my sent message now sits in my inbox.  Because I’ve got quite a few filters, I’m not sure which one is doing this—is there a way to see which filters have been applied to an email in Gmail?


I coded my own website and uploaded to a host. Some days ago I realized that in front page suddenly redirects to an unknown websites, until 3-4 redirects.  The redirects ends up at: http://59016823.g05.info/?p=NGNmN2JjNTYyNmIwMGE3YTU5MjgzNmNiOWNjOWMzNGF8MXxEaXJlY3RMaW5rfFRYbFBZbVoxWTJGMFpTQkNiMlI1VEdGNVpYST18MTAwMHw1OTAxNjgyMw==


Find the fundamental solution of $x^2 - 95y^2 = 1$ and of $x^2 - 74y^2 = 1$.

I'm trying to practice finding the fundamental solution of Pell Equations, but have not found efficient ways of finding fundamental solutions. However, it seems that using  would provide an effective way of finding these solutions, according to the link. To better understand how to actually use continued fractions through examples (with numbers),      How would you find the fundamental solution of $x^2 - 95y^2 = 1$ and of $x^2 - 74y^2 = 1$ using continued fractions?


Ubuntu Software doesn't work and why are there two Software Center in Ubuntu 20.04?

I completely erased the old disk data and installed the 20.04 LTS version of Ubuntu but the Ubuntu software on the dock doesn't start. Then I ran in the terminal:  sudo apt install --reinstall ubuntu-software   It went fine. But still it doesn't open. Then I searched in dash for "software" and found two software center. One named Software and other Ubuntu Software. Software starts but Ubuntu Software doesn't start. In the dock there is Ubuntu Software which doesn't start.    Another thing, Running sudo apt update says All packages are up to date but in the Software it shows 2 updates needed. This is strange.    Why there are two software centers? One of them starts and the other doesn't. The one which starts shows pending updates but in terminal there is no pending updates.  Update: According to first answer I ran snap-store form terminal and got this:  16:30:11:0219 Gtk Failed to load module "canberra-gtk-module" 16:30:11:0225 Gtk Failed to load module "canberra-gtk-module" 16:30:14:0571 Gs  plugin appstream took 3.0 seconds to do setup 16:30:14:0580 Gs  enabled plugins: desktop-categories, fwupd, os-release, packagekit, packagekit-local, packagekit-offline, packagekit-proxy, packagekit-refine-repos, packagekit-refresh, packagekit-upgrade, packagekit-url-to-app, appstream, desktop-menu-path, hardcoded-blacklist, hardcoded-popular, modalias, odrs, packagekit-refine, rewrite-resource, packagekit-history, provenance, snap, systemd-updates, generic-updates, provenance-license, icons, key-colors, key-colors-metadata 16:30:14:0581 Gs  disabled plugins: dpkg, dummy, fedora-langpacks, fedora-pkgdb-collections, repos 16:30:16:0144 Gs  /etc/PackageKit/Vendor.conf file not found 16:30:17:0235 Gtk Could not load a pixbuf from icon theme. This may indicate that pixbuf loaders or the mime database could not be found. ** Gtk:ERROR:../gtk/gtkiconhelper.c:494:ensure_surface_for_gicon: assertion failed (error == NULL): Failed to load /snap/snap-store/433/data-dir/icons/Yaru/16x16/status/image-missing.png: Unrecognized image file format (gdk-pixbuf-error-quark, 3) Bail out! Gtk:ERROR:../gtk/gtkiconhelper.c:494:ensure_surface_for_gicon: assertion failed (error == NULL): Failed to load /snap/snap-store/433/data-dir/icons/Yaru/16x16/status/image-missing.png: Unrecognized image file format (gdk-pixbuf-error-quark, 3) Aborted (core dumped)


What is the largest 'sequential' prime number?

New to this, sorry for bad formatting but:  The largest know prime number is a Mersenne Prime Number, i.e. it is in the form $2^n-1$. Whilst this is big, the last known prime number before this was millions of digits shorter. Take the list $2, 3, 5, 7, 11,\cdots$ in the list $11$ is the largest (prime) number. We know all the prime numbers before $11$, though. So, a better way to ask would be as stated below:  What is the largest prime number where we know all the prime numbers before it? Doing some research, I've found that we know the first $50$ million primes or so, but I'm sure with all the computing power we humans have, that cannot be the limit.


I would like to ask for help regarding writting bibliography. In bibliography section the Latex compiler puts huge gaps between the words. I would be grateful if someone could tell me how to get rid off them.  The code:  \begin{thebibliography}{99}     \bibitem{tesla}     \emph{Model S $\mid$ Tesla}.Tesla [online].[cit. 2017-04-29]. Dostupné z: https://www.tesla.com/models  \end{thebibliography}


Is there a smart precise way to determine LCM of  $C(n,1) , C(n,2) , C(n,3) ,\ldots, C(n,k)$ :  Here $C(n,k)$ denotes no. of combinations of n objects taken k at a time.


Cell life: division for immortality or reproduction with aging

Are the two cells that are derived from one cell, ‘twin sisters’ or a ‘mother and a daughter’?  In other words, can a cell really be divided to live an "immortal" life or is cell reproduction the reality of cell life that accounts cell age difference between two successive generations, cell aging-associated senescence in cell reproduction, and cell line survival after the death of old cells.


I'm trying to figure out how to get all the left cosets of subgroup $S_{3}$ generated by $(1,2)$. I know what $\langle (1,2) \rangle = \{ (0,0),(1,2) \}$. I'm just not sure how the answer key got $(1,3)\langle(1,2) \rangle = \{ (1,3), (1,2,3) \}$ and $(2,3) \langle (1,2) \rangle = \{ (2,3), (1,3,2) \}$


I am a member of a writing website called HubPages. We are each given a subdomain on which to write articles and are also given access to Google Webmaster Tools for our subdomain.  Upon checking out my stats in Webmaster Tools, I see that Google is running into some 404 errors for two reasons:   I took down an article Google (or someone) got the url totally wrong.   I am essentially getting view-only access for webmaster tools (HubPages must have set it up to allow view only so that a user doesn't mess things up) so I can't submit a url removal request to Google.  Could this be hurting the SEO for my subdomain? If not, are there other problems that could occur for me or for HubPages by leaving these URLs as is and not submitting a removal request? Should HubPages be submitting url removal requests to Google for dead or incorrect urls?


Can I use a present-tense verb when writing about a past event?

My sentence is     In Charles Dickens' book Oliver Twist, the stingy orphanage director doles out just one small bit of soup to the hungry orphans.   The main question is should it be doles or doled? Could it be either?


How to find list of available shells by command-line?

How to list available shells for use by command-line?


Intuitively proof that intensity of a wave is proportional to the square of its amplitude

Firstly I would like to know if this is valid for every kind of wave, or are there any conditions/exceptions where this is not valid.  But the main question is, is it possible to prove this fact for a general wave intuitively, rather than taking specific waves and deriving equations and showing it?


I cant get the correct values of list in function returns python

I have a function get_board to fill a 2d list with increasing numbers.  size= int (input("Size"))  def get_board(size):    i=0    num=0    board = [[0] * size] * size    for i in range(size):       j=0       for j in range(size):         board[i][j]=num         num+=1    return board  board= get_board(size)  print (board[0][0])   I cant get the correct values. If the size is 3, board starts with 6 7 8. The example board[0][0] is equal to 6. I didnt get that.


Is $\dfrac{0}{0}$ indeterminate with respect to limit only or in general?

Is $\dfrac{0}{0}$ indeterminate with respect to limit only like $\lim_{x\to 0}\dfrac{\sin x}{x}$ or it is indeterminate in general like $\log_1 1$?  I asked this because I encountered indeterminates only in limits, we don't talk about in other areas.  Like $\log_1 1$ can be any real number.


Setting up limits of integration in this double integral

$$\int \int xy dA$$ where D is the region bounded by $y = x - 1$ and parabola $y^{2} = 2x + 6$  Quick question, what does the integrand represent? I see that 5,4 is an intersection point, but 5 * 4 = 20 and I'm not sure what the integrand is even supposed to represent. Anyway here's how I set up the double integral: $$\int_{-1}^{5} \int_{x-1}^{2x+6} xy \,dy \,dx$$ $$\int_{-1}^{5} \int_{x-1}^{2x+6} (y+1)y \,dy \,dx$$ $$\int_{-1}^{5} \int_{x-1}^{2x+6} (y^2 + y \,dy \,dx$$ $$\int_{-1}^{5} \left[(\frac{y^3}{3} + \frac{y^2}{2})\right]_{-2}^{4} \,dy \,dx$$


Implementing versioning system with MySQL

I know this has been asked  and , but I have the same idea with a different possible implementation and I need some help.  Initially I had my blogstories table with this structure:  | Column    | Type        | Description                                    | |-----------|-------------|------------------------------------------------| | uid       | varchar(15) | 15 characters unique generated id              | | title     | varchar(60) | story title                                    | | content   | longtext    | story content                                  | | author    | varchar(10) | id of the user that originally wrote the story | | timestamp | int         | integer generated with microtime()             |   After I decided I wanted to implement some versioning system for every story on the blog, the first thing that came to my mind was creating a different table to hold edits; after that, I thought I could modify the existing table to hold versions instead of edits. This is the structure that came to my mind:  | Column        | Type          | Description                                       | |------------   |-------------  |------------------------------------------------   | | story_id      | varchar(15)   | 15 characters unique generated id                 | | version_id    | varchar(5)    | 5 characters unique generated id                  | | editor_id     | varchar(10)   | id of the user that commited                      | | author_id     | varchar(10)   | id of the user that originally wrote the story    | | timestamp     | int           | integer generated with microtime()                | | title         | varchar(60)   | current story title                               | | content       | longtext      | current story text                                | | coverimg      | varchar(20)   | cover image name                                  |   The reasons why I came here:   The uid field of the initial table was UNIQUE in the table. Now, the story_id is not unique anymore. How should I deal with that? (I thought I could address story_id = x and then find the latest version, but that seems very resource consuming, so please give your advice) author_id field value is repeating in each every row of the table. Where and how should I keep it?     Edit  The unique codes generation process is in the CreateUniqueCode function:  trait UIDFactory {   public function CryptoRand(int $min, int $max): int {     $range = $max - $min;     if ($range < 1) return $min;     $log = ceil(log($range, 2));     $bytes = (int) ($log / 8) + 1;     $bits = (int) $log + 1;     $filter = (int) (1 << $bits) - 1;     do {         $rnd = hexdec(bin2hex(openssl_random_pseudo_bytes($bytes)));         $rnd = $rnd & $filter;     } while ($rnd >= $range);     return $min + $rnd;   }   public function CreateUID(int $length): string {     $token = "";     $codeAlphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";     $codeAlphabet.= "abcdefghijklmnopqrstuvwxyz";     $codeAlphabet.= "0123456789";     $max = strlen($codeAlphabet) - 1;     for ($i=0; $i < $length; $i++) {         $token .= $codeAlphabet[$this->CryptoRand(0, $max)];     }     return $token;   } }   The code is written in , and was originally written in PHP by  in his .  The fields author_id and editor_id can be different, because there are users with enough permissions to edit anyone's stories.


I have a pointer declared in my header file witch i am initializing in my constructor to point towards and array. However I cant seem to get it to point towards the array as a whole instead i only see the first value in the debugger. Is there anyway to make it show everything or do i have to acces it in the blind.  I am using Visual Studio 2013  .h  class myClass{     public:         myClass();         ~MyClass();     private:         double* categories; }   };  .cpp  double array[5] = {0,1,2,3,4};  categories = new double[5] categories = array;   What confuses me is when i do it all in .cpp i can see everything just fine :/  double g[2] = { 9, 8 }; double(*j)[2] = &g;


How do I resolve apt GPG error NO_PUBKEY?

I do not recall why I have download.opensuse.org, but I am OK just removing whatever is causing this error:  W: GPG error: http://download.opensuse.org  Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6FE3AE1CC7D68E37   This does not appear to be a duplicate question because the solutions proposed in other similar questions are not working here:  # sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 6FE3AE1CC7D68E37 Executing: gpg --ignore-time-conflict --no-options --no-default-keyring --secret-keyring /tmp/tmp.OCmHCQ908W --trustdb-name /etc/apt/trustdb.gpg --keyring /etc/apt/trusted.gpg --primary-keyring /etc/apt/trusted.gpg --keyserver keyserver.ubuntu.com --recv-keys 6FE3AE1CC7D68E37 gpg: requesting key C7D68E37 from hkp server keyserver.ubuntu.com gpgkeys: key 6FE3AE1CC7D68E37 not found on keyserver gpg: no valid OpenPGP data found. gpg: Total number processed: 0   I'm on 12.04