I am trying to write a simple command line "word guessing game" with an Array of colors. The problem is that it won't break out of the do/while loop with my current IF statement even when the correct color is chosen.  import java.util.Random; import java.util.Scanner;  public class ColorGuess {      public static void main(String[] args) {          Scanner input = new Scanner(System.in);               String[] colors = { "red", "blue", "green", "yellow", "purple",                 "pink", "white", "black", "brown", "orange", "grey" };          String colorGuess;          Random rand = new Random();         int randColor = rand.nextInt(colors.length);         String color = colors[randColor];          System.out.printf("Guess the color: ");          do {             colorGuess = input.nextLine();             if (color == colorGuess) {                 break;             } else {                 System.out.printf("Sorry, try again: ");             }         } while (colorGuess != color);          System.out.println("You got it! The color was indeed " + color + ".");      }  }


Button with onclick event created by setAttribute does not start a function when clicked

Everything is working just fine until the "pause button" is created (last line of code), I set onclick event on it with function "pauseAudio" however when I click on it "Uncaught ReferenceError: pauseAudio is not defined at HTMLButtonElement.onclick" I dont see a reason why it's not working. function myFunction5(){     var audio = new Audio("jazz.mp3" ) ;      function playAudio() {       audio.play();}       playAudio();       function pauseAudio() {         audio.pause();}    document.getElementById("rockbtn").classList.replace("btn-secondary-rock", "btnfadeout");   document.getElementById("animebtn").classList.replace("btn-secondary-anime", "btnfadeoutanime");     document.getElementById("popbtn").classList.replace("btn-secondary-pop", "btnfadeoutpop");     document.getElementById("90sbtn").classList.replace("btn-secondary-90s", "btnfadeout90s");       document.getElementById("classicbtn").classList.replace("btn-secondary-classic", "btnfadeoutclassic");         document.getElementById("hiphopbtn").classList.replace("btn-secondary-hiphop", "btnfadeouthiphop");         document.getElementById("electrobtn").classList.replace("btn-secondary-electro", "btnfadeoutelectro");             document.getElementById("jazzbtn").classList.replace("btn-secondary-jazz", "btnfadeoutjazz");                 document.getElementById("firstbb").classList.replace("super", "superjazz");          document.getElementById("rockbtn").classList.remove('btn-secondary-1');      function myFunction13() {           var node = document.createElement("P");       var textnode = document.createTextNode("Oh a Jazz lover, thats wonderfull");       node.appendChild(textnode);       document.getElementById("firstbb").appendChild(node);     }     myFunction13();     var xx = document.getElementById("firstbb").lastChild.setAttribute("id", "democlassjazz");       function myFunction14() {           var node = document.createElement("P");       var textnode = document.createTextNode("U can always change music by clicking the bell");       node.appendChild(textnode);       document.getElementById("firstbb").appendChild(node);}        setTimeout(function(){myFunction14();       var xx = document.getElementById("firstbb").lastChild.setAttribute("id", "democlassjazz");},11200)         function myFunction15() {             var node = document.createElement("LABEL");             var textnode = document.createTextNode("music");             node.appendChild(textnode);         document.getElementById("firstbb").appendChild(node);}   setTimeout(function(){         myFunction15();         var xx = document.getElementById("firstbb").lastChild.setAttribute("class", "fab fa-sellsy icon ");},11900)  setTimeout(function(){ var xx = document.getElementById("firstbb").lastChild.setAttribute("class", "fab fa-sellsy  iconmovingcloud");},13500 ) setTimeout(function(){ var xx = document.getElementById("firstbb").lastChild.setAttribute("for", "menu-toggle");},13500 )           setTimeout(function(){  var node = document.createElement("BUTTON");         var textnode = document.createTextNode("blablabla");         node.appendChild(textnode);         document.getElementById("firstbb").appendChild(node);},13600) setTimeout(function(){ var xx = document.getElementById("firstbb").lastChild.setAttribute("onclick", "pauseAudio()");},13700 )     }


Example of convex nonlinear equality constraint

I know that affine equalities such as  $$a_1 x_1 + a_2 x_2 + a_3 x_3 = b_3$$  are convex. I'm wondering whether there are nonlinear equality constraints, for instance something like  $$a_1 x_1 + a_2 x_2 + a_3 x_3 = b_3 + x^{2p},\quad p \in N$$  or even something like  $$x_1 = x_2^2$$  Are these kinds of equality constraint also convex? Can you give me any other example showing non-affine convex functions? Thanks!


Can the Grave Domain cleric's Spare the Dying cantrip still be cast as a regular action?

The  (Xanathar's Guide to Everything, p. 19-20) gets the Circle of Mortality feature at 1st level, part of which states:     In addition, you learn the  cantrip, which doesn’t count against the number of cleric cantrips you know. For you, it has a range of 30 feet, and you can cast it as a bonus action.   This wording seems to imply the option, rather than necessity, to cast it as a bonus action. Am I correct in assuming this? Can I still cast it as an action and have my bonus action available?


Why "flag" a question when I have access to "close"?

As :       If you have the privilege to cast close votes, it doesn't matter at all if you do it via the 'close' link or via the 'flag' link and   the option 'Should be closed ...'. It will count as a close vote, not   a flag. The 'close' link is just a 'shortcut' for an action which is   quite often necessary.      If you don't have the privilege, then you don't see the close link at all. Flag -> 'Should be closed ...' will count as a flag, not a   close vote.   Recently I got access to the close link and I still have access to the flag link. It makes me befuddled to choose which one if I find a problematic question. I think the SE should remove "flag" for users that reached +3k reputations.    Why should I flag it if I have access to vote to close a question?


Remove extra spaces from left and right of a text

In my website, I have title that is kind of like this:  <title>Current Title &rarr; Sub Title &rarr; My Site</title>   I want to display the Sub Title part of the title in some of my html elements... so I wrote this JavaScript code to print the title, but only the text in between the 1st and 2nd &rarr;  &quot;<script>document.write(document.title.split("\u2192")[1]);</script>&quot;   But that code outputs " Sub Title " with a space in front and behind it. Do you know how I can somehow delete the 2 spaces using javascript (without changing the title) to output something like this: "Sub Title"?  Thanks!


Python: Ignore comments of a text file which is parsed to a dictionary to write in a CSV

I'm parsing a text file into few dictionaries so that I can write them to a CSV file. But now I have comments in the text file. How do I ignore the comment lines and work with rest of the content? I have checked few posts which recommend Pandas read_csv but it  will work after I have a dataframe. I need to ignore the comments and read the rest content before parsing.  EDIT: I'm concerned with sql comments: -- and /* ....  */    Part of my code: (form is a grammar defined by me)  with open("xyz.txt", 'r') as file:               if re.search(r'select|SELECT', file.read()):             print("hello select")             a = form.parseString(open('xyz.txt').read());             z=a.asDict()   Text file:  /*this is a multi line comment which  needs to be ignored */ select book from tab where b=100 --single line comment which should be ignored select sal from emp where job_id=101   I tried using startswith(#) for single line comment but the code kept on running and no result..and I have no idea for multi line comments.  with open("xyz.txt", 'r') as file:       for line in file:             li=line.strip()             if not li.startswith("#"):                 new=line.rstrip()       while new:                 if re.search(r'select|SELECT', file.read()):             print("hello select")             a = form.parseString(open('xyz.txt').read());             z=a.asDict()


How can I upgrade Ubuntu from 19.10 to 20.04 without losing packages?

When I upgraded from 18.10 to 19.04, and again when I upgraded from 19.04 to 19.10, I had to manually reinstall all of the packages I installed through dpkg, apt, etc. (I do not recall the precise details of how I went about either upgrade.) Is there a less painful route to upgrade Ubuntu 19.10 to 20.04?  Closely related: When I was a macOS user and upgraded my system software, I could export a list of installed Mac Ports, and then reinstall after the system upgrade using that exported list. Is there a similar kind of functionality for dpkg or apt? I would find this kind of solution to be "less painful" in case there is not a simple and direct way to accomplish an upgrade to 20.04 without losing installed packages. :)


How can I install latest version of Cinnamon in Ubuntu?

My computer's OS and desktop environment are:  Ubuntu 20.04 (focal) 64 bit  Cinnamon Desktop 4.4.8   Here is a screenshot of my system (sorry, it's French, it's ok if you don't know french to see it):  The latest version of Cinnamon is 4.6.6, and I want to update to that version. My question is simple: How can I update to Cinnamon 4.6.6 without reinstalling Cinnamon? NOTE: This question does not anwser my question:


Notify users when they are mentioned (on meta)

As I have been learning the ropes here on Meta, I have been reading and sometimes participating in discussions similar to  where other users have been mentioned by name and berated or mocked for some bad/gaming behaviour. Other times I've seen users simply just commented upon with "I've noticed that this user has a tendency to do link-only self-answers, what should I do?", and I have found myself thinking: "I wonder if they've ever said something similar about me?"  A couple of days ago, as part of  discussion, where a specific user is mentioned for supposedly poor reviewing another user made this comment to the OP:     -1. Exposing another user like this is not appropriate IMHO. You could just post the image without the link to his profile   The OP defended his position and I made a comment backing the OP, because the site favours substantiating claims with facts; especially on Meta those facts are frequently specific (sets of) questions and occasionally specific (sets of) users' behaviour. That is just how things are done, but I do think the objection is valid because when you are linking to a user profile you are targeting that specific user, and not some general behaviour.  So I suggest that one of the abilities that should come with perhaps 1000 or 1500 rep is that the "Responses" on your profile is expanded with "Links/Mentions" - and that this list is populated with mentions (in questions/answers/comments) where somebody have linked your profile.   The point being two-fold:   The community is no longer discussing/snickering behind said users backs, but are offering the criticism more directly. The user in question have a chance to know that something is not done right, and can act to improve (or defend) it, even when the behaviour is not bad enough to warrant intervention by system or mods. Also, when/if the behaviour improves, the user can flag the links to be removed as obsolete - and hence won't continue to be the laughing stock of everybody who happens to read the post.    The reason I think some reputation is required is from the assumption that more seasoned users will have thicker skin and hence handle the criticism better. I realise that some users will be beyond reach, but I think others would gain from it - and even without the gain, I do feel we all have a right to know when we are being discussed in the open.  Note that this suggestion is NOT for @-mentions in comments, but for links to user profiles.


What's the word for someone who doesn't appreciate what he has and wants more?

What's the word for someone who is ungrateful/ not appreciative of the things he has but wants more lavish things? For example, instead of appreciating the little things he has in his life, someone might go on and on, complaining about things like how the scratch on his brand new shoe ruined his day or who wants a new car while complaining about his old one.


Fibonacci in python, recursively into a list

I am practicing with some code, and one thing I am trying to do is have the Fibonacci sequence placed recursively into a list. I have managed to do it without recursion, but that is not too difficult. Thank you to anyone who can offer any help.   #python 2  arr = [1, 1] n=15 def Fib(n):   tmp = arr[-1] + arr[-2]   if n == 0:     return 0 #base case 1   elif n == 1:     return 1  #base case 2   else:     return Fib(n-1) + Fib(n-2) #recursive call   arr.append(tmp)   return arr Fib(n) print arr


Getting the name of the currently executing method

Is there a way to get the name of the currently executing method in Java?


My laptop is Acer Aspire1 A111-31, 4GB DDR4 RAM, Operating System: Windows 10 Home 64-bit,  Processor: Intel(R) Celeron(R) N4000 CPU @ 1.10GHz (2 CPUs), ~1.1GHz,  Card name: Intel(R) UHD Graphics 600


How can I scale the content of an iframe?

How can I scale the content of an iframe (in my example it is an HTML page, and is not a popup) in a page of my web site?  For example, I want to display the content that appears in the iframe at 80% of the original size.


Show that the equation $\displaystyle 3^x+4^x=5^x$ has exactly one root  I proved it graphically but I am in need of an analytic solution


How do I disable the profiles button in Chrome?

Since Chrome version 38, there's a pretty ugly button in the title bar of the Chrome window that allows you to switch profiles quickly.  Since I'm the only one that uses my computer, this is not really useful to me, and I'd rather reclaim the space for more open tabs.  I've looked in the settings but don't see a way to disable it.  How can I get rid of the button?


sir, over department created a host file to run over office program in windows, but they give us dell system having operating system ubuntu 16.4 now my question is that how this add file in ubuntu to run the program. the windows command is given below  TO ACCESS FIORI - Please Follow the Instructions in this Video  Path:- C:\Windows\System32\drivers\etc  Copy attached Hosts File in the above path.  Fiori Link to access SAP in Google Chrome:


So I want to summon lapis using a command block in 1.12.2 But I don't know what ID it is. I tried Lapis lazuli and dye4 and dyeblue and bluedye and dye_4 and nothing worked.


The statement I'm trying to prove is:     $(x+y)^c\le x^c+y^c$ whenever $0\le x,y$ and $0\le c\le1$.   This comes up in the proof that $|x|_*^c$ is an absolute value whenever $0<c\le1$ and $|x|_*$ is an absolute value over some integral domain $D$. The given statement, however, is simply a question about a real inequality. How do you prove this one?  The case $x=0$ or $y=0$ is trivial, so we can assume that $x,y>0$. Then expanding the definitions we have $e^{c\log(x+y)}\le e^{c\log x}+e^{c\log y}$, but the addition doesn't play well with the exponentials and logs, so I don't see what else can be done. This feels like a convexity result, but I'm not seeing exactly how to make the connection (not to mention that I still haven't proved that $\exp$ is convex and $\log$ is concave, so if I can avoid that I'd prefer to).


How to Enable Root Login on Ubuntu 17.04

Can anyone please guide me on how to enable root login in Ubuntu 17.04?


Python/Json dump extra backslashes in data

Are my expectations incorrect?  output desired is for a this single field "{\"escapeChar\":\"\\\", \"quoteChar\":\"\"\", \"separatorChar\":\",\"}"  input csv text "{""escapeChar"":""\\"", ""quoteChar"":""\"""", ""separatorChar"":"",""}"  Code: obj_str = json.dumps(table_obj).replace('RS Target Table', 'Table Name').replace('Stage Table', 'input_table')  #Get obj back with replacement  BANG!! obj = json.loads(obj_str)  print ('after loads, source_serde_params: ',   obj['source_serde_params']) with open(filename, 'w' ) as write_file:                     json.dump(obj, write_file,  indent=2)  console: after loads, source_serde_params:  {"escapeChar":"\\", "quoteChar":"\"", "separatorChar":","}  output file: "source_serde_params": "{\"escapeChar\":\"\\\\\", \"quoteChar\":\"\\\"\", \"separatorChar\":\",\"}"  python 3.7.9 windows laptop


Why does a new directory have a hard link count of 2 before anything is added to it?

Say I just create directory newDirectory and then I do ls -ld command. I see that the number of hard links is 2. What exactly makes the hard link 2 from the start? Also is the number of subdirectories in the current directory equal to the number of hard links - 2?


Is It “Category URLs” or “Categories URLs”

I want to talk about several categories. Each category has only one URL.  Which one is correct and why?   Category URLs Categories URL Categories URLs


What happens when a moderator clicks 'leave open' in the close-vote queue?

It takes  clicking "leave open" in the close-vote queue to remove the question from the queue.  How about diamond mods?  Do they remove it from the queue in one click, or not?


Identify this novel: youngsters psychologically tested for abilities/profession, hero wants to author the tests, society uses moving walkways

I'm trying to find a book I heard about once.  Little is known:    it was already in print in 1990's there were moving walkways (used for chasing in one scene) hero was predetermined to work as cleaner/sweeper, wanted to become an author of these tests ("books", "long books") that were used to determine profession,  and it was revealed that those who don't pass the test are actually rare genius.   It sounds much close to "Brave New World" or Gattaca's scenario, or Heinleins "Roads must roll", but is neither.    The most reason I'm interested in finding this book is, that Iar Elterrus's novels (these I'm currently worshipping) contains a ton of references to such plot, and I want to discourage myself knowing if the plot was actually "stolen" or not.  Also, references to such universes (psychological screening, massively genetic prenatal-tested society?) are welcome in comments even if they don't match the full request.


Deleting a question showed one of the answer as deleted by the owner

I have deleted a  (the link is for 10k users on Drupal Answers), and one of the answer is shown as deleted by the owner, which is not what happened, as I deleted the question, and (indirectly) all the answers.    There was also a pending undelete vote it was not present before I deleted the question; when I voted to undelete it the answer was effectively undeleted. (The answer is now shown as deleted, for those who can see the question I am referring.) Still, I don't understand how there could be an undelete vote, when the answer was not deleted, before I deleted the question.  When I deleted the question, Dave Reid was reported to be seen 18 hours before I deleted it. He could have not deleted his own answer in the same moment I was deleting the question.  Update  Looking at  (the link is for 10k users on Drupal Answers), I notice the following.    What happened is that effectively the author of the answer deleted the answer, but then undeleted it. When I deleted the question, the system remembered the undelete vote casted from the author, but it didn't remember that vote already had effect; in fact, when I undeleted the answer, the answer is said to be undeleted from the author, and from me (third entry in the screenshot), when it was just me to undelete it because the user logged in 18 hours before I deleted the question.


How do I create a section in the dashboard w/ an input field

I want to create an input field in the dashboard where I can put in links or text which will update a section I define on the actual website. I know I can just edit the template but I want to make things easier for the client.  To be a bit more specific, I have a 'latest updates' section in the header and the client has requested that he'd like to update this manually. So I'd like to create an input box of some sort in the dashboard so he can easily enter text (or links), click save, and have it reflected on the website (in the header).  Can someone give me a starting point?


Why is the Magical world kept hidden from the Muggle world?

In the Harry Potter universe, there is a huge effort to hide the Wizarding world from the Muggle world. From the Platform 9 3/4 at King's Cross Station, to Diagon Alley, to the Knight Bus, everything was made so that the Muggles couldn't detect them.  Why was this really necessary?    In Potterverse, magic was a real thing with thousands of years of proven history. So, it could provide a wealth of knowledge for Muggles.  One answer could be that magic might scare Muggles.  But, I don't think it would after thousands of years. It would be no different than any other new and revolutionary technology. After a reasonable duration, Muggles could become used to it.


This seems to occur on all Stack Exchange sites and I'm not going to provide any specific examples as that is basically naming and shaming. However, as many of you who work the review queues know, and maybe even some people who submit content to the review queues to be reviewed; the quality and consistency of some reviewers is substandard.  Some general examples:   Edits that improve posts being rejected as "an attempt to reply to the post" Reviewers that have approved 100% of all suggested edits they've ever reviewed, even when others have tried to reject them (ie: they just keep clicking Accept for everything) Reviewers who click "No Action Required" for spam and off topic posts   Is there anything that could be implemented so that even established users get audited every now and again, with punishments for failing the audit being remembered and escalating if they keep failing future audits (up to and including perhaps revoking the privilege to work that queue)?  This isn't about one off mistakes, this is about the people who see the review queues as another source of badges and consistently apply the same action to everything just to increase a number and move a progress bar.  I feel that letting this continue as it is results in the duplication of effort on the part of the reviewers who actually pay attention when working through the queues by approving changes that shouldn't be approved, by ignoring content that needs fixing, and allowing more negative posts like spam slip through the net and stick around for longer than it had to.  Can we do something to reduce the amount of poor quality reviewers there are working the queues?


How can an element append into an empty array in java?

What I trying to do is creating an empty array such as char[] array = {};  then I have a method called append static void append(char array[], char x) {   array = Arrays.copyOf(array, array.length + 1);   array[array.length - 1] = x; }  for example, I try to append x into the empty array and it keeps throwing Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0


How are my DNS entries safe in a shared hosting environment?

I'm trying to understand how DNS works in a shared hosting environment.  I went to my registrar and set my name servers to my host's ns1.foo.com and ns2.foo.com. I'm using a cloud hosting provider who has a web portal where I can set my DNS entries. However I am confused by the lack of security. when I entered in the entries for my domain there was never any step to prove that I actually own that domain. What is to stop somebody else on the same hosting service (a nasty neighbor) from writing over my DNS entries and pointing my traffic to their server instead?


How do i make separated template declarations and implementations work?

I have some template struct defined in templates.h:  //templates.h #ifndef TEMPLATES_H #define TEMPLATES_H  template<typename Key = int, typename Value = Key>  struct array{       map<const Key, Value> data;       //Stuffs  };  /*explicit (full) specialization*/  template<> template<typename Key> struct array<Key, char>{      map<const Key, Value> data;      //Stuffs };  #include "templates.cpp"  #endif   Trying to separate declarations (interface) from definitions (implementations), i did this in templates.cpp:  //templates.cpp #ifdef TEMPLATES_H #include "templates.h" #endif  template<typename Key, char>  array<Key, char>::array(const Key& k, const char* v){ cout << "specialised array<T, char>"; }    inside main(), i test-drove:  //inside main(); array<int, char> out(1, "Just testing");      /*error 1: prototype for 'array<Key, char>::array(const Key&, const char*)' does not match any in class 'array<Key, char>'                                                 error 2: candidate is: array<Key, char>::array(const array<Key, char>&)                                                     */   Question: I expected a call to array::array(Key, char) constructor; which is an explicit specialization of array::array(Key, Value), but got the error message commented above. what am i doing wrong, or how can i fix this ?.


Coupon collector - Chance of collecting desired coupons but not a full set.

Disclaimer: I am not in a mathematics field or a mathematics professional.  I'm interested to know how many random draws it would take to have a particular chance (50%, 75% and 90%) of getting 5 specific results (out of a pool of 12 possible results) at least once each, assuming that it is possible to obtain each result more than once and that each result is equally probable.   Eg. How many times would you have to roll a 12-sided die before you had a 50% chance of rolling at least one each of the numbers 1, 2, 3, 4 and 5? How many rolls for a 75% chance? How many rolls for a 90% chance.   I know this is a variant of the coupon collector problem, but my maths is nowhere near good enough to work on the problem or to even follow many of the explanations I've found online.  While I'm primarily interested in the "5 out of 12" scenario mentioned above, I'm also curious what the formula would be for "X out of Y" where X is the number of specific results that are desirable and Y is the total number of possible results.


Why does cd need execution permission of a directory?

From      For directories, the execute permission is a little different; it means you can do things to files within that directory (e. g. read or execute them).   cd into a directory needs execution permission, but does it do something to some file in the directory, and if yes, how? The best I can think of is cd do something to the file . under the directory, but why doesn't cd just deal with the directory itself, instead of any file under it, so as to avoid needing execution permission?  Thanks.


I'm trying to put a few articles together into a small publication. Each article has been sent to me in .tex format, so I want to include them into one file, for the whole publication. My code is something like this:       \documentclass[a4paper]{article}     \usepackage{newclude}     \usepackage{docmute,subfiles}     \begin{document}     \input{article1}     \newpage     \setcounter{section}{0}     \input{article2}     \end{document}   Each article uses authblk package, so in article1, I have:      \author[1]{A}     \author[2]{B}     \affil[1]{AffilA}     \affil[2]{AffilB}   And in article2:      \author[1]{C}     \affil[1]{AffilC}   The problem is that including the files as above, the authblk package adds all the the authors, so after compilation, all authors (A,B and C) appears in the \maketitle of article2. I guess I need to reset the author list, but I can't find out how. Any ideas?


Proof that $\frac{a^2}{b} + \frac{b^2}{c} + \frac{c^2}{a} \geq a+b+c$

I've tried getting everything on the left side and transforming it into something squared so that I can prove it's bigger or equals to 0 but I've been unsuccessful.


What is the purpose of tag "blank"? burninate?

Just found one question on SO with the tag . Got intrigued and went after explanation. Found empty wiki but used in 458 questions. Edit: 241 179 150 61 50 now.  0 to go!  Some tagged it because of , others relating to , others , etc  I feel this is a confusing and not helpful tag. Can someone clarify it so we can add a wiki to it, or should this tag be burninated?


How to add one attribute column to another with a space between the two in QGIS

I am wondering if it possible to add one attribute column to another with a space between the two in QGIS. I figured out you can add them together but I need a space between the texts


What is the difference between using crontab -e and /etc/crontab

I wish to run stuff from startup and also trigger reboots using cron.  I was using sudo crontab -e and adding commands there. The commands work apart from the reboots. The reboots do not happen all the time. I wish to reboot at 4 am every morning. My added line is :  00 4 * * * root /sbin/shutdown -r now >> /var/log/daily-backup.log 2>&1   I now instead modified /etc/crontab instead for the reboots and it seems to work. Why is this? Shouldn't crontab -e work anyways because commands get run as root?


Let $\pi$ be a prime element in $\Bbb{Z}[i]$. Then $N(\pi)=2$ or $N(\pi)=p$ s.t. $p$ is prime and $p\equiv 1\pmod 4$

Let $\pi$ denote a prime element in $\Bbb{Z}[i]$ such that $\pi\not\in \Bbb{Z},i\Bbb{Z}$. Prove that $N(\pi)=2$ or $N(\pi)=p$, where $p$ is a prime number $\equiv 1\pmod4$. Give a complete classification of the prime elements of $\Bbb{Z}[i]$ using the prime numbers in $\Bbb{Z}$.   This exact question has been asked  but I do not understand the answers given, so I will ask it again in hope of further explanation.  Here's everything I know that will probably help me with the problem:   We know that $\pi=a+bi$ where $a,b\in \Bbb{Z}\setminus \{ 0\}$. Fermat's Two Square theorem: A prime number $p\equiv 1 \mod4$ satisfies $p=a^2+b^2$ where $a\neq b$ and $a,b\in \Bbb{N}\setminus    \{0\}$. $\pi$ is irreducible in $\Bbb{Z}[i]$ If $\pi=xy$ then $\pi \mid x$ or $\pi \mid y$ If $N(\pi)=2$ then $a=\pm 1, b=\pm 1$. If $N(\pi)=p$ where prime $p\equiv 1\pmod 4$ then we know $p=a+bi$ for some $a,b\in \Bbb{Z}\setminus \{0\}$ by Fermat's theorem.   I can't figure out where to start. I was thinking of starting with this:  Let $x,y\in \Bbb{Z}[i]$ such that $x=x_1+x_2 i$ and $y=y_1+y_2i$. Then $\pi\mid x$ or $\pi\mid y$. Suppose $\pi\mid x$.....   Can I have a hint on how to begin this?


Possesive pronoun used after relative clause

The man who came at yesterday's party, his car has been stolen at GIP Market.   I want to Express that   a man came in a yesterday's party and his car has been stolen by some one  from GIP Market.so is the above sentence is correct?


Stick Div to Bottom of screen till content gets longer

Stick div to bottom of screen and when the content gets longer than the screen and you have to scroll make the div go down with the content but wont come shorter than bottom of the screen.  QUESTION: How do i get a div to stick to bottom of screen and move down when the content gets longer than the screen where you have to scroll?


Today at a teachers' seminar, one of the teachers asked for fun whether zero should be followed by units (e.g. 0 metres/second or 0 metre or 0 moles). This question became a hot topic, and some teachers were saying that, yes, it should be while others were saying that it shouldn't be under certain conditions. When I came home I tried to find the answer on the Internet, but I got nothing.  Should zero be followed by units?  EDIT For Reopening: My question is not just about whether there is a dimensional analysis justification for dropping the unit after a zero (as a positive answer to  would imply), but whether and in which cases it is a good idea to do so. That you can in principle replace $0\:\mathrm{m}$ with $0$ doesn't mean that you should do so in all circumstances.


Why is the value of the reference before the null assignment returned to the calling method?

I am unable to determine why the sb object reference value that gets mirrored back to the calling method does not mirror the last value (i.e. null) that it was assigned?    public class Test{    void testRefs(String str, StringBuilder sb){     str = str + sb.toString();     sb.append(str);     System.out.println(sb);     str = null;     sb = null;     System.out.println(sb);   }     public static void main(String[] args){     String s = "aaa";     StringBuilder sb = new StringBuilder("bbb");     new Test().testRefs(s, sb);     System.out.println("s="+s+" sb="+sb);   } }


I have tried installing this package (needed for android studio).  This is the error i'm getting  E: Unable to locate package lib32bz2-1.0 E: Couldn't find any package by glob 'lib32bz2-1.0' E: Couldn't find any package by regex 'lib32bz2-1.0'   I have already tried:  sudo dpkg --add-architecture i386 sudo apt-get update sudo apt-get install lib32bz2-1.0   &  sudo dpkg --add-architecture i386 sudo apt-get update sudo apt-get install lib32bz2-1.0:i386   I also searched on  and did not find lib32bz2-1.0 for Ubuntu 16.04. So how do i get this package which is available for trusty and precise?


Which GeoTIFF tags tell me what I want to know?

I'm reading some GeoTIFF files into my app using libgeotiff. After the model of the listgeo program that comes with libgeotiff, I want to extract the extents (corners) of the GeoTIFF so I can position it.  I only really want to deal with coords in WGS84 and UTM (ultimately, I'll convert WGS84 to UTM). However, I don't know which bit of the GeoTIFF info tells me what I want to know about the 'corner' coords. Obviously, I can use the magnitude of the numbers to guess if the resulting coords are lats and longs, but surely there must be an official way?  Something like (pseudo-code):  If (geotifftag == UTM || geotifftag == WGS84)     // Proceed Else     Msg("Unrecognised data format") End If   Could anybody help me out with what the GeoTIFF tags actually tell me?


I used this code to get a pager.     if (isset($_GET['tid'])) {      $id=($_GET['tid']);      $query = new EntityFieldQuery();      $query->entityCondition('entity_type', 'node');      $query->entityCondition('bundle', 'escorts_product');      $query->pager(2,1);      $query->propertyCondition('status', 1);      $query->fieldCondition('field_product_sub_cat', 'tid', $id,'=');      $result = $query->execute();     //print "<pre>";print_r($result);     }   When I used print "<pre>";print_r($result), it gave me 2 results on y page, whereas I added more than 2; this is right.   How should I get links for next page and also previous, next? Is there any other way to get a pager?


How can an object's instantaneous speed be zero and it's instantaneous acceleration be nonzero?

I'm studying for my upcoming physics course and ran across this concept - I'd love an explanation.


How do I create an array of pointers in a class?

I'm defining a class named Roster below. I've already defined the class Student. I'm trying to create an array of pointers of type Student in the Roster class to add the students to the Roster. I'm super new to programming and C++, and I'm trying to figure out why this is giving me errors. The IDE is saying it expects a ; before the * and it's missing a type specifier, which doesn't make sense to me. Thanks in advance for any help! class Roster { private:     int studentIndex = -1;     const static int numStudents = 5;     Student* classRosterArray[numStudents]; public:     void parse(string row);


Story identification : abandoned martian village with a high pitched note playing from nowhere

I was writing , and it reminded me of a short story, which I can't recall the title.  Here is the pitch :   An astronaut is the only survivor of the crash of its ship on Mars, he only has some food rations and a bottle of water He finds an abandoned village The village is absolutely unfriendly with the astronaut There is a high-pitched sound playing from nowhere. Later in the story the astronaut realizes that it is some sort of music aliens would enjoy The sinks in the houses produces some sort of goo. When the character tries to eat it he becomes sick, even shower throw some sort of acid water The astronaut tries to sleep on the ground of a house but he sweats a lot He then realizes the village is learning from him to suit its needs, but the village is self destroying   This story was in a short story collection book, which was quite old so I suppose it was written before 1980.


El Capitan froze and rebooted (Macbook Pro Retina Mid 2012)

2.3 Ghz Intel Core i7 8GB DDR3: Was running NetAdmin Pro which is monitoring  my office LAN, processors consumption was at  ~15 - 20%. Simultaneously I ran WiFI Explorer,  3.7% no more than 5% CPU usage. And I was  updating Xcode to v 7.3.1 and was browsing and  watching video from playground.ru Watch the videos until half of it (20mins) the Video froze I moved the mouse and turned out  the whole OSX is frozen. littleSnitch v 3.7 has no reaction I immediately pull the Ethernet adaptor and  MacBook just went to black screen. I then  switch off the wireless router. (My MacBook Pro  is connected to the network via Ethernet  adaptor and via WiFi router bearing different IP, I was thinking of cutting both network  communication, in case it was an intrusion) MacBook just restarted itself to login screen,  after 15-20 sec of black screen and total  silence) I again restarted and booted into Recovery  mode use disk utility. After completing disk  check. Login and previously opened programs resume  back (NetAdmin Pro, WiFi Explorer, Yandex  browser, Activity Monitor and AppStore) AppStore doesn't resume the download  everything else is functioning normally and in Addition I have got my calendar open after login (I did not launch accidental nor was it set to  start with system login)   Question 1: Are there any way to know what was happening and what was OS El Capitan last reaction before it froze and rebooted?  Question 2: Are there any software better than "Console" v10.11 to interpret what was going on before it crashes?  P.S. Thank you in advance, I will try to upload the Console messages later from the MacBook Pro    DDT-2:~ Chaleune$ syslog | grep -i "shutdown cause"  Jun 22 14:15:37 DDT-2 kernel[0] <Notice>: Previous shutdown cause: 5  Jun 22 20:34:46 localhost kernel[0] <Notice>: Previous shutdown cause: 5  Jun 23 15:18:23 DDT-2 kernel[0] <Notice>: Previous shutdown cause: 5  Jun 24 17:58:32 localhost kernel[0] <Notice>: Previous shutdown cause: 5  Jun 24 20:09:52 localhost kernel[0] <Notice>: Previous shutdown cause: 5  Jun 24 22:58:15 localhost kernel[0] <Notice>: Previous shutdown cause: 5Jun 25 14:43:36 DDT-2 kernel[0] <Notice>: Previous shutdown cause: 5  Jun 25 21:55:31 localhost kernel[0] <Notice>: Previous shutdown cause: 3  Jun 25 22:20:57 localhost kernel[0] <Notice>: Kext com.apple.driver.AppleOSXWatchdog failed to load (0xdc008012).Previous shutdown cause: 5  Jun 26 10:18:44 localhost kernel[0] <Notice>: Previous shutdown cause: 5  Jun 26 12:09:45 localhost kernel[0] <Notice>: Previous shutdown cause: 5  Jun 26 18:00:31 localhost kernel[0] <Notice>: Previous shutdown cause: 5  Jun 27 13:05:58 DDT-2 kernel[0] <Notice>: Previous shutdown cause: 5  Jun 27 22:56:11 localhost kernel[0] <Notice>: Previous shutdown cause: 5  Jun 28 14:18:27 DDT-2 kernel[0] <Notice>: Previous shutdown cause: 5  *Jun 29 18:56:21 localhost kernel[0] <Notice>: Previous shutdown cause: -128*  Jun 29 23:31:22 DDT-2 kernel[0] <Notice>: Previous shutdown cause: -128      shows the following   dsIllInstErr                  = 3,    /illegal instruction error/ dsChkErr                      = 5,    /check trap error/ userCanceledErr               = -128    gave the following interpretation:   03 Illegal Instruction The computer has a specific vocabulary of machine language instructions it can understand. If a computer tries to execute an instruction that isn't in its vocabulary, you see this error code. It's less likely than error 02, but still very common. 05 Range Check Error Programmers can use an instruction in the Motorola 68000 to check if a number is within a certain range. This error indicates that the number tested isn't in the specified range. -128  userCanceledErr         User canceled an operation


Where I can get a tablet with Ubuntu, or I could use Ubuntu on any tablet that meets requirement?

I'm just wondering Does Ubuntu sell the tablets or can I buy one with the right requirements and put Ubuntu on to it as the new operating system??


Ubuntu 18.04 not booting after Windows 10 install

After installing Windows 10 on a new hard drive, Ubuntu 18.04 will no longer boot.  The computer boots to Grub 2.02, but to a version I'm not familiar with, showing the EFI images.    Choosing the different options results in the following:   "EFI/ubuntu/fwupx64.efi" returns me to the menu, with no message "EFI/ubuntu/mmx64.efi" shows Shim UEFI key management screen All "efi/Efi//.efi" options result in a file not found error The Windows options boot to Windows correctly   I've tried Boot-Repair a couple of times with no luck. The last report from Boot-Repair can be found .   Is there any way to completely reinstall the EFI setup?   Update: Running grub-mkconfig produces the same incorrect menu entries. The config is generated using the files in /etc/grub.d. My directory only contained /etc/grub.d/25_custom, which is the only file in that directory. It looks like my /etc/grub.d templates are hosed, and I need to find a way to regenerate them. Is there a command to rebuild these templates?


Let's say I have the following in Python:  class Test():     self.value1 = 1     self.value2 = 2  def setvalue1(self, value):     self.value1 = value   So one can set up value1 by doing:  Test.setvalue1('Hola')   or  Test.Value1 = 'Hola'   So far so good. My problem is I would like to set the values by reading them somewhere else so for instance I could have the following:  A = [['Value1','Hola'],['Value2','Adios']]   I would like to be able to run something that will do (in pseudo code):  for each in A:     Test.each[0] = A[1]   Is this possible? Thanks so much!


Is this plagiarism or common way of expression?

I have submitted my essay via Turnitin. Subsequently a similarity report was generated where all similar bits in my work were flagged up with the work of others. There is one bit flagged up where I did not cite. Is it considered plagiarism? This is what I wrote:  This theory is applicable to educational institutions where students have limited exposure to L2 culture, for instance they do not live in an area where L2 is spoken.  Below is the source which Turnitin compared my words with:  Visual media can provide a valuable source of authentic input for students who do not live in the country where the L2 is spoken.  The words in bold are the bits flagged up by Turnitin. On a side note, 'this theory' in my sentence does not refer to the same argument in the source. In my opinion it is just that the author of the source and I happened to use the same expression to describe people who do not live in an L2-speaking area. When I was writing this essay, I did not even know the existence of the source! I hope it is not considered plagiarism. Although the same phrase was used, the two sentences mean different things!


Which phrase is more suitable to convey one's inability to do something — "not able to" or "unable to"? For example,        not able to join the meeting   unable to join the meeting


i am currently working with a school task by making a webpage, but i can't seem to figure out how to align an image/icon with the other buttons in the navbar. I have tried to finsd the answer, but i can't seem to find the answer after several google search. Also, i am limited to html and css only and not allowed to use tools like bootstrap. my code for this page is below:  HTML code: <!DOCTYPE html>         <meta charset="utf-8">     <title>Zero hunger</title>     <link rel="stylesheet" href="css/master.css">

Home

Contact

Game

Hello World

      CSS code: body{   margin: 0;   font-family: sans-serif;  }  /*Navbar*/ nav ul{   margin: 0;   padding: 0;   text-align: center;   background-color: #D09E37; } nav ul li{   list-style: none;   display:inline-block;  } nav ul li.nav-button{   padding: 0 15px; } nav ul li.nav-button:hover{   background-color: #bf8000; } nav ul li a{   text-decoration: none;   font-size: 1.5em;   color: white;   line-height: 54px; } .nav-img{   height: 58px;   display: inline-block; }


I am trying to download files from .  The URL is:   When I use this command:  wget http://www.ncbi.nlm.nih.gov/geo/download/?acc=GSE48191&format=file    I get only index.html?acc=GSE48191 which is some kind of binary format.  How can I download the files from this HTTP site?


HP Pavillion 17-e67cl Black screen Ubuntu 14.04, only boots with vga in

During the boot up of the livecd of ubuntu, the screen was black.  I connected the computer to VGA to see what was happening. Once ubuntu started up (I used the try ubuntu option) I could then see everything so I disconnected the VGA.  I installed it fine. I then turn on the computer to find that it stays at a black screen and from the fans and lack of login sound, I know that it is stuck at some startup process. (I had it set to log in automatically) I try again with the vga attached and it went in perfectly to the desktop and the desktop showed on the laptop screen again.  I tried setting the Grub to nosetmode and have had no luck researching this problem. The black screen is on grub, the loading screen, and the login screen. (The lock screen and login screen work fine if you log out or lock computer, only a problem when just turning computer on)  The 2 issues:   Needs VGA to load ubuntu Screen shows black during everything before login.   Computer: HP Pavillion 17-e67cl Ubuntu: 14.04-LTS  This is getting marked as a duplicate when in fact it is not a duplicate, please read fully through a question before setting it to duplicate moderators. I already had a reply claiming it was a duplicate and I explained that nomodeset did not work. The solution in the other thread does not work, I need a new solution. I did however get another reply which I will be testing soon. I also wrote that there are 2 issues, UBUNTU will not start up unless vga is plugged in, I can tell this by the fans. When i tried recovery mode and did failsafe graphics it had an error code. No Monitor Attatched. This is a laptop therefore there is clearly a monitor attatched. The computer does not read the laptop monitor as being attatched until I am logged in.


Quantile of t distribution when the degree of freedom increases

I have a little issue : I want to prove that if $\{X_n\}_{n \in \mathbb N}$ is a sequence of random variables defined on a probability space $(\Omega, \mathcal{F}, \mathbb{P})$ such that $\forall n \in \mathbb{N}, X_n \sim \mathcal{T}_n$ then $\forall \alpha > 0, \{\mathbb{P}(X_n \leq \alpha)\}_{n \in \mathbb{N}}$ is an increasing sequence.  I tried to express this probability using the density function : $$\forall \alpha > 0, \mathbb{P}(X_n \leq \alpha) = \frac{1}{2} + \int_{0}^\alpha f_n(t) d\lambda(t)$$ when $f_n$ stands for the density (according to Lebesgue measure) of $X_n$ and then use results on integrale depending of a parameter but it led to a lot of calculations...


Validate a username and password against Active Directory?

How can I validate a username and password against Active Directory? I simply want to check if a username and password are correct.


Is there any rule as to what is used in the beginning of a sentence, 'I' or 'Me'?  Example: 1) I and x are good friends.          2) Me and x are good friends.  Which is correct? Or are both of these correct?


Consideration of fields to be used in SOQL Group By

I have come to know that a few fields in Salesforce.com are not groupable and that we can make sure whether field is group-able or not with getDescribeSObject.  I would like to know what are the consideration for determining whether field is group-able or not.


Understanding a lemma regarding subspace topology

I am learning topology and am struggling with some of the concepts of open sets regarding subspaces.  The problem I am working on says, that Y is a subspace of X, and A is a subset of Y, then show that the topology A inherits as a subspace of Y is the same topology it inherits as a subspace from X.  now what I am trying to prove is that A is a basis for the subspace topology of Y of X, and A is the basis for the subspace topology on X, then these two topologies are the same.  Here is the lemma I am struggling to utilize , it says, "Let Y be a subspace of X, if U is open in Y and Y is open in X, then U is open in X."  Since A is a subset of Y, does this imply that A is open in Y? (i think so). Y is open in X, so does this imply that A is open in X? (I think so)  If A is open in Y, and A is open in X, does this mean that A is open in $Y \bigcap U$ for $U \subset X$ ?  (This I am not sure of).  Further, assuming my intuition is right,  if A is open in $Y \bigcap U$ does this mean for $x \in Y \bigcap U$ that $x \in A \bigcap U$ since A is open in both Y and X?    this yields my needed argument saying that $A \bigcap U \subset Y \bigcap U$  this can then be shown that $\mathbb{B}_{A}$ is a basis for both topologies. my question is that just because A is a subset of Y and A is open in X, and $x \in Y \bigcap U$ , I am not sure if this implies that $x \in A \bigcap U$.  Thank you again so very much and I will greatly appreciate any clarification.


Finding the maximum $lcm$ of a set of numbers with sum $n$

Consider all possible values for $(a_1,\ldots,a_n)$ (where each $a_i$ may be a positive integer or 0) when  $a_1 + \cdots + a_n = n$.  Consider $(a_j,\ldots,a_k)$ the values in $(a_1,\ldots,a_n)$ which are non-zero.  Given a set of values for all $a_i$, $j\le i\le k$ can we check whether they maximise $\operatorname{lcm}(a_j,\ldots,a_k)$ without testing all other cases?  Is there a computationally viable way  to always pick values for all $a_i$ which maximise $\operatorname{lcm}(a_1,\ldots,a_k)$?


Here is a question:  For measurable set $E$ and $F$, with positive measure (in the sense of Lebesgue measure), prove that there is an open interval in the set $E+F$.   I know this is a question from Stein's Real analysis. The point is that I don't know how to prove it using Fubini's theorem. Thanks in advance.


Applying Styles To ListItems in CheckBoxList

How can styles be applied to CheckBoxList ListItems.  Unlike other controls, such as the Repeater where you can specify <ItemStyle>, you can't seem to specify a style for each individual control.  Is there some sort of work around?


How many numbers less than $m$ and relatively prime to $n$, where $m>n$?

Let $m$ and $n$ be two integers such that $m>n$. Then find the number of integers less than $m$ and relatively prime to $n$.    I had come across a problem of this type with specific values for $m$ and $n$, unfortunately, the values I don't remember anymore. So I asked this general question. How to solve this type of question?   My thoughts are that we need to count the numbers. So we can count the number of integers less than $m$ and relatively prime to $m$ using Euler's totient function. Now among those numbers, also belongs the numbers which are relatively prime to $n$. We can also find the numbers less than $n$ and relatively prime to $n$. That will give a rough estimation. But how do we know about the actual number of such integers? Can anybody help me with this?   Thanks.


I am making a New Year Standee and would like to know what the bleed space should be. I am making the creative in Illustrator. Kindly help


Calling non static method in static method

I am having a little issue with my code. I am trying to find the runtime to compare to some math that I have prepared for the problem. I have one method in particular that I am testing that goes like this:   public static int foo(int n, int k){         long startTime = System.nanoTime();         if(n<=k){             long endTime = System.nanoTime();             System.out.println("checkFoo");             System.out.println("start time: " +startTime);             System.out.println("end time: " +endTime);             return 1;         }         else{             return foo(n/k,k) + 1;         }     }   I test this code in my main method in the following way:   public static void main(String[] args){     foo(1, 1);     foo(5, 1);      foo(10, 1);     foo(100, 1); }   I get an error where it says   Exception in thread "main" java.lang.StackOverflowError   and then it repeats the line:  at Problem3.foo(Problem3.java:42)    I am wondering if this has to do with the fact that foo is supposed to return an int and maybe I am just not calling the function correctly. If that is the case, what is considered the correct way to call this function so that it also prints out the information that I need it to? Or is this error completely different than how I am understanding it to be?


How to check which app uses GPS on Galaxy Nexus?

I'm constantly seeing the Searching for GPS... icon in my status bar, and would like to check which app is trying to access my location. I checked the similar questions on the site and all suggested either Spare Parts or the test menu.  However, on my Galaxy Nexus these are out of the question, since Spare Parts crashes with ANR when I try to access the battery stats (there's no com.android.settings.battery_history.BatteryHistory activity), and the test menu doesn't have the necessary menus.  So, any other possibilities?


What's happened to the site statistics on Stack Overflow?

The visits and views on Stack Overflow have vanished before January 2018.   What's happened to them? Are we going to have them restored?


Does a solid suspended in beaker filled with Air increase the weight of the beaker?

When a solid object is suspended in a beaker filled with water placed on a weighing machine, the reading increases and but the object is suspended in a beaker filled with air, the reading does not increase. What is the reason behind this.


Can a PC use a mirror or other sight enhancer to use sacred flame at a target around a corner?

We have a PC that is getting very sneaky with his Sacred Flame application. Its fun outside-the-box play but if he carries a hand mirror or uses scrying spells its going to become far easier.  Can a mirror allow use of Sacred Flame around a corner?  Can a PC scry to the other side of a door and use this sight to activate sacred flame?   Rules for Total cover:     A target with total cover can’t be targeted directly by an attack or a spell, although some spells can reach such a target by including it in an area of effect. (PHB 196)   Sacred Flame Text:     Flame-like radiance descends on a creature that you can see within range. The target must succeed on a Dexterity saving throw or take 1d8 radiant damage. The target gains no benefit from cover for this saving throw. (PHB 272)   Sacred flame specifically states "that you can see".   It is also confusing what the "area of effect" might be.


How to Straighten Curved UVs into Straight Belt

Showing the actual 3D model of a curving ramp.  Shows the UVs of that model that blender did automatically. Shows the UV image that I need.   I am going put a road texture on it., but round faces are not helping me at all. All I need is straight belt kind of UV.


Is there a way to find out specifically why a flight was delayed?

Is there some tool I can use to figure out why a flight is delayed?  Specifically I'm trying to see why the 2nd leg of the flight AI 951 is delayed by about an hour nearly every day, though it takes off on time.


how to make this Table with multiple rows

Hi all how i could make this table in latex?? i tried but no luck   here is the code i try:  \documentclass[letterpaper]{article} \usepackage[english]{babel} \usepackage{color} \usepackage{array} \usepackage{supertabular} \usepackage{hhline}  \begin{document} \begin{center} \tablelasttail{} \begin{supertabular}{m{26.7mm}m{50.53mm}|m{41.66mm}|m{49.01mm}|} \hline \multicolumn{1}{|m{26.7mm}|}{{\selectlanguage{english} Main Topic}} & {\selectlanguage{english} Topic} & {\selectlanguage{english} Sub Topic} & {\selectlanguage{english} Publication}\\\hline \multicolumn{1}{|m{26.7mm}|}{{\selectlanguage{english} A}} & {\selectlanguage{english} A1} & ~  & {\selectlanguage{english} 1}\\\hline  & {\selectlanguage{english} A2} & ~  & {\selectlanguage{english} 2}\\\hhline{~---}  &  &  & {\selectlanguage{english} 3}\\\hhline{~~~-}  &  &  & {\selectlanguage{english} 4}\\\hhline{~~~-}  & {\selectlanguage{english} A3} & {\selectlanguage{english} E1} & {\selectlanguage{english} 5}\\\hhline{~---}  &  &  & {\selectlanguage{english} 6}\\\hhline{~~~-}  &  &  & {\selectlanguage{english} 7}\\\hhline{~~~-}  &  &  & {\selectlanguage{english} 8}\\\hhline{~~~-}  &  & {\selectlanguage{english} E2} & {\selectlanguage{english} 9}\\\hhline{~~--}  &  &  & {\selectlanguage{english} 10}\\\hhline{~~~-}  &  & {\selectlanguage{english} E3} & {\selectlanguage{english} 11}\\\hhline{~~--}  &  &  & {\selectlanguage{english} 12}\\\hhline{~~~-} \multicolumn{1}{|m{26.7mm}|}{{\selectlanguage{english} B}} & {\selectlanguage{english} B1} & ~  & {\selectlanguage{english} 13}\\\hline  & {\selectlanguage{english} B2} & ~  & {\selectlanguage{english} 14}\\\hhline{~---} \end{supertabular} \end{center} \end{document}


What does "focal length multiplier" mean?

I have heard of something called a focal length multiplier, particularly in connection with the size of the image sensor in a camera.  What I don't understand is what this is and why ans how it is related to the size of the sensor.  Can anyone please explain this?


Global uniqueness and determinism in classical mechanics

Something always bugged me about Newton's equations (or, equivalently, Euler-Lagrange/Hamilton's): Determinism, which is the philosophical framework of classical mechanics, requires that, by completely knowing the state of a system at a given instant, $\textbf{x}(t_0)$ and the law by which the system evolves, which, in dynamics, looks something like $$m\ddot{\textbf{x}}=f(\textbf{x},\dot{\textbf{x}},t)$$ You know the exact state of the system at any instant, forwards in time and, when defined, backwards. But global uniqueness theorems state that, for this to be true, the function $f$ needs some properties, namely that it doesn't "blow up" anywhere in the domain (iirc it's enough for $f$ to be uniformly continous). My question then can be posed as such: are there any systems in which the forces that naturally arise violate the global existence/uniqueness theorems? And if so, then what does this tell us about the system?


Adding a query string to menu items determined by the current node?

I'm pretty new to Drupal 8.  I'm trying to figure out how to programmatically add a query string to a menu item link, the specific query string is determined by the node/page the user is currently on.  For example, I've got a link on my primary menu that goes to   If I'm on the 'about me' page I want the link to add a query string of '?origin=about'. ()  If I'm on the 'contact me' page I want the link to add '?origin=contact', etc.  Are there any modules where this can be done, or how might I go about doing this myself?


How do I find where a curve hits the $xy$ plane with vectors?

I need to find $r'(t)$ and $||r'(t)||$ of $r(t)=<t,t,t^2>$, and tell where the curve hits the $xy$ plane (if it does). Also, I need to say something about how the curve looks like (do I just plot some points and figure out how it looks like?). I understand how to find $r'(t)$ and $||r'(t)||$, but how do I tell where the curve hits the $xy$ plane, and how do I describe the curve?  Here are my solutions for $r'(t)$ and $||r'(t)||$:    $r(t)=<t,t,t^2>$  $r'(t) = <1,1,2t>$     $||r'(t)||=\sqrt{2+4t^2}$


Full solution of the quantum particle on a ring

In  , the general solution for the wavefunction, with $k = R \sqrt{2 m E / \hbar^2}$, $R$ being the ring radius, $c_{+, -}$ being constants, $E$ the energy, and $m$ the particle mass, is  $$\psi(\theta) = c_{+} e^{i k \theta} +  c_{-} e^{-i k \theta}$$  Periodic boundary conditions give the eigenvalues $k = n$, with $n=0, \pm 1, \pm 2, \ldots$.  At first glance the problem looks "underdetermined" - it seems that there are two unknowns ($c_{+}$ and $c_{-}$) but only one condition to find them, normalization of the wavefunction $\langle \psi \lvert \psi\rangle = 1$. But in my naive understanding, the problem is actually not underdetermined because one may set $c_{-} = 0$, as is seemingly done on  in order to normalize the wavefunction.  Why may one set $c_{-} = 0$? Or, why do  and textbooks (below) seemingly set $c_{-} = 0$? And how can we treat the general case with $c_{-} \ne 0$?  Even if we do not trust , most textbooks on introductory quantum look at the ring problem and do the same thing. For example:   "Introduction to Quantum Mechanics: in Chemistry, Materials Science, and Biology" By Sy M. Blinder "Atkins' Physical Chemistry" By Peter Atkins, Julio de Paula "Quantum Mechanics for Chemists" David O. Hayward "Case studies in atomic physics 4" edited by E. McDaniel "Quantum Chemistry" By John P. Lowe


How do I find the square root of complex number $7-(6\sqrt2)i$?   I hope there's someone who can show me the method. Thanks in advance.


Show that a complete metric space without isolated points is uncountable

I've seen a few questions already posted on here, but they all deal with perfect subsets and being Hausdorff, both of which are topics we haven't covered yet.  I know that a point a is isolated if $\{a\}$ is open (aka there exists $\epsilon > 0$ s.t. $B_{\epsilon}(a) = \{a\}$.  I am supposed to consider singletons and then use Baire Category Theorem.  Could someone help me with where to start?


Find the limit: $$\lim_{x\to0^+}{x^x}$$  *This question appeared in a calculus exam, and I would like to see different approaches and solutions to the problem.


How can I find the fundamental solution to the following PDE in $R^3$: $$-\Delta + 1 = 0$$. So far I have that $\hat{u} = \frac{1}{1-|s|^2}$, but how can i get the inverse FT in 3D. Any help is appreciated.


Dual Boot Windows 10 and Linux Ubuntu on Separate Hard Drives

How would I go about dual booting Windows 10 and Ubuntu, the windows drive is on an ssd as my c drive and my s drive is a hdd that I want to use for Linux. I have no idea what I need to download it or anything.


Waiting for background programs to close- fix?

I have this problem:    I've had it for a couple of years, but now my computer always does this, and the only program which is ever shown on this screen is Skype. I've tried to reinstall Skype, but this hasn't solved this issue, so I don't really know where to fix this...  I'm normally good with computers and pretty much an expert, but this has stumped me.   Is there a way to make Windows immediately terminate the background programs without showing me this screen (it really annoys me sometimes, and sometimes hangs for 30 seconds or more), or to fix this problem within Skype?  My computer is a laptop and it's pretty fast, but it's pretty much dwarfed by newer computers (the laptop is a 4 year old Medion Akoya X7811 with 1st-gen Core i7) and it shouldn't be doing this. Almost every program runs fine on it, yet it always stalls on this screen.  Yes, I know this question has been asked before, but I would generally like to make Skype stop causing this problem (is there a way to switch it to a foreground process?) instead of modifying the registry. This laptop is my primary laptop and I use it for my business, and do not want to break it.  I'm not sure if this site is the right place to ask this question, if it isn't, please notify me instead of downvoting my question.


I'd like to cut a hexagonal cylinder into 8 parts. I don't understand why the cut isn't going all around it, but instead it is just on one face. Anyone know how to fix this?


When I run:  tar -zxvf john-1.7.0.2.tar.gz   I get this:  gzip: stdin: not in gzip format tar: Child returned status 1 tar: Error is not recoverable: exiting now   It should start unpacking.  Some people told me not to use the z but I get the same error.  It's a file that I downloaded this way:  wget http://openwall.com/john/f/john-1.7.0.2.tar.gz


A tutorial shows cp -r   but   only shows -R.


Prove that the prime factors $p$ of $n=x^2+y^2$ of the form $p=4m+3$ can only have even exponents.

I'm looking for an elementary proof of the statement in the title. Actually I have already proved that if $-\bar{1}$ is a square then $p\equiv 1 \pmod 4$ or $p=2$. I try to deduce from this statement that if $p=4m+3$ is a prime factor of $n$ then $p$ can only have an even exponent. I know that I can prove it using Gaussian integers, but I'm really trying to do it using only the previous result.


What is the title of a short story about boy who becomes a tree?

This sci-fi short story was written by a female in the 60s. A missionary persuades a roly-poly young boy to skip a coming of age ritual where the teenagers (all roly-poly and energetic) are hung from gnarled trees with boulders during the beginning of flood season. They all stretch out into skinny low energy adults. The missionary convinces one boy to skip the ritual.  The boy bends over, grabs his ankles and transforms into one of the gnarled trees. I think title of story contains word "suffering"


How to search for all questions with bounties across the network?

I wanted to search for questions on all SE sites that had a bounty. I am not sure if it is possible, and if it is how can I?   I have seen other questions that show how to find questions on each individual site, but how can I find all of them in one search from the homepage stackexchange.com? If this has been asked already, please let me know.  It has been suggested that the question was already asked (click  for the question), but that question only showed how to find those questions on each separate site or some complex way to search. I am hoping to find a way to search for bountied questions easily or for someone to create a way to do this.


I bought a used iPhone 4.  The previous owner re-set the phone, but did not remove the device from their iCloud.  It is asking me for their iCloud information when I try to set-up the phone.  I don't have contact with the previous owner anymore.  Is there a way to remove the device from their iCloud so I can use a new one?


TSQL: Using parameter with tablename in function

Using SQL Server 2014...  I'm trying to convert this code to be used in a function...   SET @sqlCommand = N'SELECT @text = ' + @fieldname + ' FROM ' + @tablename +' WHERE ID=''' + CONVERT(NVARCHAR(200), @ID)  + '''' EXECUTE sp_executesql...   ...but functions doesn't accept sp_executesql.  How can I in a function get data from a table where the tablename is coming from a parameter?


How do I prove that $ E[X] = \int _{0}^\infty (1-F_x(t))dt $


We have 4K=a+bc and 6k=b+ac, but I've tried (a+b)(a-b) or expand it directly. Neither of them works... Got trapped


In a normal extension of a field, is there an automorphism that maps irreducible factors of a certain irreducible polynomial?

Let $F$ be a field, $f(x)$ be an irreducible polynomial in $F[x]$ and $E/F$ be a normal extension. Show that if $g(x)$, $h(x)$ are irreducible factors of $f(x)$ in $E[x]$ then there exists an automorphism $\sigma$ of $E$ over $F$ such that $\sigma(g)=h$. Does this result hold if we do not assume normal extension?  What I've tried so far:  Let $\overline{F}$ be the algebraic closure of $F$. Then, by definition, $f(x)\in F[x]$ splits completely over $\overline{F}$. So  $$f(x)=(x-\alpha_1)\cdots(x-\alpha_n)(x-\beta_1)\cdots(x-\beta_m) (x-\gamma_1)\cdots(x-\gamma_k)$$  Since $g(x)$ and $h(x)$ are irreducible factors of $f(x)\in E[x]$ then we can write, without loss of generality, $n\leq m$ and   $$g(x)=(x-\alpha_1)\cdots(x-\alpha_n)\qquad h(x)=(x-\beta_1)\cdots(x-\beta_m)$$  I want to define a map $\sigma:E\rightarrow E$ which maps $\alpha_i$ to $\beta_i$ (with this I can conclude $\sigma(g)=h$, right?). But the problems are:  1) I don't know $n=m$.  2) I don't know $\alpha_i,\beta_i\in E$.  3) Even if $\alpha_i,\beta_i\in E$, I'd only have a map on a subset of $E$. I don't know if I can extend this map to the whole $E$.  EDIT: The question above can be found on Serge Lang's Algebra, Revised Third Edition, Volme 1, Chapter V, exercise 26, and is stated as:     Let $k$ be a field, $f(X)$ an irreducible polynomial in $k[X]$, and   let $K$ be a finite normal extension of $k$. If $g$, $h$ are monic   irreducible factors of $f(X)$ in $K[X]$, show that there exists an   automorphism $\sigma$ of $K$ over $k$ such that $\sigma = h^\sigma$.   Give an example when this conclusion is not valid if $K$ is not normal   over $k$.


I recently bought myself a Windows 10 gaming computer and I downloaded MC on it. It works until I try to open a world or server and crashes giving me this message:  Completely ignored arguments: [--nativeLauncherVersion, 301] [19:24:28] [Client thread/INFO]: Setting user: Vek05 [19:24:28] [Client thread/INFO]: (Session ID is <censored>) [19:24:29] [Client thread/INFO]: LWJGL Version: 2.9.4 [19:24:29] [Client thread/INFO]: Reloading ResourceManager: Default [19:24:30] [Sound Library Loader/INFO]: Starting up SoundSystem... [19:24:30] [Thread-4/INFO]: Initializing LWJGL OpenAL [19:24:30] [Thread-4/INFO]: (The LWJGL binding of OpenAL.  For more information, see http://www.lwjgl.org) [19:24:30] [Thread-4/INFO]: OpenAL initialized. [19:24:30] [Sound Library Loader/INFO]: Sound engine started [19:24:31] [Client thread/INFO]: Created: 1024x512 textures-atlas [19:24:42] [Server thread/INFO]: Starting integrated minecraft server version 1.9 [19:24:42] [Server thread/INFO]: Generating keypair [19:24:42] [Server thread/INFO]: Preparing start region for level 0 [19:24:43] [Server thread/INFO]: Preparing spawn area: 10% [19:24:44] [Server thread/INFO]: Preparing spawn area: 22% [19:24:45] [Server thread/INFO]: Preparing spawn area: 34% [19:24:46] [Server thread/INFO]: Preparing spawn area: 48% [19:24:47] [Server thread/INFO]: Preparing spawn area: 61% [19:24:48] [Server thread/INFO]: Preparing spawn area: 72% [19:24:49] [Server thread/INFO]: Preparing spawn area: 83% [19:24:50] [Server thread/INFO]: Preparing spawn area: 97% [19:24:50] [Server thread/INFO]: Changing view distance to 12, from 10 [19:24:51] [Server thread/INFO]: Vek05[local:E:0e11365e] logged in with entity id 236 at (244.5, 98.0, 265.5) [19:24:51] [Server thread/INFO]: Vek05 joined the game [19:24:55] [Server thread/WARN]: Can't keep up! Did the system time change, or is the server overloaded? Running 4073ms behind, skipping 81 tick(s) # # A fatal error has been detected by the Java Runtime Environment: # #  EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x00007ffe9ca0d76c, pid=9492, tid=7700 # # JRE version: Java(TM) SE Runtime Environment (8.0_25-b18) (build 1.8.0_25-b18) # Java VM: Java HotSpot(TM) 64-Bit Server VM (25.25-b02 mixed mode windows-amd64 compressed oops) # Problematic frame: # C  [ig9icd64.dll+0x56d76c] # # Failed to write core dump. Minidumps are not enabled by default on client versions of Windows # # An error report file with more information is saved as: # C:\Users\vince\AppData\Roaming\.minecraft\hs_err_pid9492.log # # If you would like to submit a bug report, please visit: #   http://bugreport.sun.com/bugreport/crash.jsp # The crash happened outside the Java Virtual Machine in native code. # See problematic frame for where to report the bug. # AL lib: (EE) alc_cleanup: 1 device not closed Java HotSpot(TM) 64-Bit Server VM warning: Using incremental CMS is deprecated and will likely be removed in a future release   What does it mean and how can I fix this?


Technical term for "make like a banana" & "make like a tree" idioms

These are two part terms - where the endings are usually left off:  make like a banana make like a tree  The endings though are where the point lies:  (make like a banana) and split (make like a tree) and leave  Wikitonary just tags these as idiomatic. Is there a technical term for these phrases? Edit: does it count as an aposiopesis?


I want to create a custom mouse pointer on Ubuntu 16.04 from icons .How do I do it?


Schengen visa: Must I enter and leave the Schengen area in the same country?

I live in London and  am planning to visit France and Brussels. I'm applying in French embassy, showing hotel booking in France and I will stay there three nights and 4th day morning I will travel to Brussels and will leave Brussels around evening.   Do I need to go back to Paris for coming back to London or can I directly a take train from Brussels to London?  Also do I need to show (to the embassy) a ticket for traveling to Brussels from Paris?


How to show a table with 10+ columns in android

since the android screen is small to show a table with 10+ columns  so, I was wondering what is the best approach to show this kind of table according to material design guidlines The data from website that should be shown in android looks like this:


Currency fields show other values on a page that in the database

I am confused by the behaviour of Currency fields in Multi-Currency environments. My app does a calculation on day X and stores its result in a record.  The custom page which displays a SUM of those values should always display the same as a database query. But...it does not. If I change Exchanges Rates those values change.  Was it wrong to store currency values in a Currency field, am I querying incorrectly or do I need to display a values that is manually calculated?  How does Multi-Currency and Currency fields work together? When are currency values converted and which conversion rate is taken into account?  I am confused?!


"Contribute for" or "Contribute to" or "Contribute on" or "Contribute in"

We said :      I do want to thank Mr. Foulen and Mr. Felten who contribute for   server hosting .   or     I do want to thank Mr. Foulen and Mr. Felten who contribute to   server hosting .   or     I do want to thank Mr. Foulen and Mr. Felten who contribute on   server hosting .   or     I do want to thank Mr. Foulen and Mr. Felten who contribute in   server hosting .


Linux: coloring bash prompt will break carriage return

When I try to colorize the bash prompt like this:  export PS1="\e[0;31m[\u@\h \W]\$ \e[m "   it breaks the carriage return (instead of going to a new line when line is full, it starts in the same line and erases the input text).  If I remove the color sequence it works fine. I use Ubuntu 11.10 and terminal (guake has the same bug too).


I'm searching for a word representing "Negatively surprising", or "Negatively amused" in an appropriate form. Example: Someone who proclaims he aims to do things in the right way has done something in the completely opposite way.    How could you have done such a thing? That action is very ___.   Said with the purpose of showing the contrast between the expected and the actual, and asking for change to adhere with his set goals, instead of just pointing out disappointment.  It is different from  because it asks there about surprise of being affected by the disappointment. The meaning of surprise here is different.


How to concatenate multiple short parameters to a single string using bash?

I would like to concatenate multiple parameters to a single string in bash like this: $ ls -latr $ cp -Rv directory1 directory2  The best I can do is something like this: while (( ${#} )) do     case "${1}" in         "-h" | "--help")             getScriptUsage             exit 0             ;;          "-i" | "--include-alpha-builds")             include_alpha_build_versions="true"             ;;          "-r" | "--redownload")             removeAllFiles             ;;          "-t" | "--torbrowser-version")             tarball_filename_version="${2}"             shift             ;;          "-v" | "--version")             getVersion             ;;          *)             getScriptUsage             /bin/echo -e "\e[01;31mParameter '${1}' not found.\e[0m"             exit 1     esac      shift || break done   But with that, I can only append the parameters: $ torbrowser -i -r -t 9.5  Might be off topic: I also would like to be able to mix parameters around, like in cp: $ cp directory1 directory2 -Rv $ cp -Rv directory1 directory2


Why does the size of an int vary in some compilers?

Reading the following resource it says the size of an int/pointer can vary depending on the compiler:    Why is this?  I understand C defines only the min and max number of what a type should hold, but why would one compiler choose to set for example int to 2 bytes and another at 4? What would be the advantage of one over another?


For some reason biblatex isn't working properly.  It seems it can't reference the .bib file, and thus doesn't print the citations properly.  The strange thing is that I have an older .tex file that uses biblatex with the same sequence of commands, and it works.  For some reason this new one doesn't work.  In any case, here is my MWE:  \documentclass{article} \usepackage[backend=biber]{biblatex} \addbibresource{edrefs.bib} \begin{document} This is the main\footcite{Edg} text.\footcite[32]{SkilFR} \cite{Edg} \nocite{*} \printbibliography \end{document}   And the .bib file:   @mvbook   {Edg,   AUTHOR = "Edgerton, Franklin",   TITLE = "{Buddhist Hybrid Sanskrit Grammar and Dictionary}",   VOLUMEs = 2,   PUBLISHER = "Yale University Press",   LOCATION = "New Haven",   YEAR = 1953   }     @article    {SkilFR,    author = "Skilton, Andrew",    title = "{Four Recensions of the Samādhirājasūtra}",    journaltitle = "{Indo-Iranian Journal}",   pages = "335--356",   volume = 42,   number = 4,   year = 1999,   publisher = "Klewer",   location = "Netherlands"   }


Can't post question on Stack Overflow. Says "this looks like spam"

I have been a long time user of Stack Overflow and have just today signed up to post a question. The question description is quite long, does not reference any outside sites, but when I go to post it, I get a message saying "This looks like spam".    All of the detail in my question is necessary for full understanding of the problem, so how do I get this question posted? I can send the question detail, or if your system saves the question before it is actually posted, then you can look at my only question entitled "SQL tricky query to update contact id".  I have made the following screenshots:  ...  What do I need to do so I can post my question on Stack Overflow?


Characteristic roots of Circulant Matrix

Given a matrix of order $n \times n$ $$ A=   \begin{bmatrix}     a_1 & a_2 & ... & a_n \\     a_n & a_1 & ... & a_{n-2}\\     \vdots & \vdots & \vdots & \vdots\\     a_2 & a_3 & ... & a_1   \end{bmatrix} $$ Show that the characteristic roots of $A$ are $$a_1 + a_2w_i + a_3w_i^2 + ... + a_nw_i^{n-1},$$ for $i = 1, ... , n;$ where $\omega_1, \omega_2, ... , \omega_n$ are the $n^{th}$ roots of unity.


According to Newton's Law of Universal Gravitation, why isn't the universe shrinking?

Every point mass is attracted to each other with a force $F= \frac{GMm}{r^2}$. I know nothing about theories behind expanding universes but, why wouldn't the universe eventually shrink down to a minuscule space?


Etiquette on sending a thank you e-mail to respondents who gave me helpful information

Sometimes there are cases in a e-mail correspondence with academia staff (professors and bureaucrats) in which I don't know which is the best practice. I wonder if there is any best practice for the following cases:  Reply to a reply: when I ask for information via e-mail, and the reply gives me all the information I want, should I send an email just to thank them, or is this considered a bad, time-consuming practice?   How does a professor react to this kind of reply? And what about a bureaucrat (who maybe receives more e-mail)?  If I asked for an internship and he gave me a negative response, is not replying to him considered rude or normal?


Java Swing Components Init NullPointerException

I'm trying to have a simple app that lets you pick some files and does some logic with them. I've created the interface via the JFrame Palette builder incorporated in IntelliJ IDEA.  public class App extends JFrame implements ActionListener { JPanel panelComponent; private JButton buttonFolder; private JTextPane textPane; private JPanel myPanel; private JButton buttonCreatePackage; private JTextField textFieldFolder; private JLabel nameFolderUnderContentLabel; private JButton buttonAdd; private JPanel panelList; private JScrollPane scrollPane; private JPanel consolePanel; private JScrollPane tableScrollPane; private JTable table1;    }  This is how my App class looks, it being the main point of the application. None of the fields are defined with the "new" initialiser, because IntelliJ does this automatically for me, if I click the see the usages of a component (see the following screenshot):   So, I have my App that extends JFrame, my JButtons that are initialised and binded by the IDE, and I start it like this:    public static void main(String[] args) {     SwingUtilities.invokeLater(() -> {             myApp = new App();             myApp.setVisible(true);             control = true;             myApp.initViews();             myApp.document = (StyledDocument) myApp.textPane.getDocument();             myApp.buttonCreatePackage.setEnabled(false);             myApp.documentWriter = new DocumentWriter(myApp.document);             myApp.setContentPane(myApp.myPanel);         worker.execute();     }); }   What happens, inside the initViews method I'm setting listeners, but it throws a NullPointerException. Inside the method it just looks like this:   buttonFolder.addActionListener(e -> {         //code   }  The exception:  Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException  Clicking on the error, it points me to the line where I set the actionListener on the buttonFolder.  My theory is that somehow there's a collision between the initial thread of the app, the EDT thread where the GUI should be done/edited, and the creation of components between them.  I've checked if the initViews is called on the EDT thread, and the answer is yes. I've tried initialising the views in a Swing worker to explicitly force it on the EDT thread, but it did not work. I've also tried postponing the adding of listeners and such for 200-400ms to give the GUI to init, and i've had no success.  Looking forward to any input, Thank you.


Are the sticks of RAM in my desktop computer volatile? Is it safe to sell them?

I have two sticks of RAM in my computer that I would like to sell or donate. From what I understand some RAM is volatile, losing all its contents when power is gone for a few minutes, and some is non-volatile, retaining that information after power is lost. I would like to know which kind of RAM I have and whether it is safe to give it to someone else. I am not very tech savvy, all I know about the sticks is that the manufacturer is Kingston, and when I open Task Manager it says that it is "DDR3" and the form factor is "DIMM". Thanks in advance.


Why was 29 megabits per second not fast enough to download a game like 'Tell Me Why', which is 9 GB in size?

Although my computer received 29 megabits per second, 29 millions bits per second, why did it take me a long time to download a 9 gigabyte game? For example, the 'Tell Me Why' game.


Difference between 'ls' and 'echo $(ls)'

Consider the two shell samples  $ ls myDoc.html SomeDirectory someDoc.txt   and  $ echo $(ls) myDoc.html SomeDirectory someDoc.txt   The first executes ls which, as I understand, appends the contents of the current working directory to the stdout file (which is what the terminal displays).  Is this correct?  The second takes the value of the ls command (which means is the contents of the current working directory) and prints it to the stdout file. Is this correct?  Why do the two commands give different outputs?


Remote lecturing: best software approach

With the recent outbreak of covid-19 many of us will need to think about remote means of teaching.  The option for me that seems ideal would be the capacity to broadcast exactly what is on my screen to a a large audience (a minimum of a couple of dozen).  There seems to me an ideal solution, but there are a dizzying number of options available, many of which do not quite fit that spec. Software that is free and readily available to educational institutions (such as something on google apps) would be ideal of course.


Which lines do change after a sync in /proc/meminfo ?

I was taught, that the sync command writes the data stored within the cache of the RAM onto hard-disk, this release should be displayed in /proc/meminfo. However when I cat /proc/meminfo before and after a sync I can not see any difference, the line with buffers and cage stays the same.   Where can I actually see the change ?


I know that many of here can be confused with my question because as we all know, and was also well mentioned in the books, that Voldemort never valued love.  But I wonder if why he revenged and killed his father.     One of my possible theory of the impossibility for Tom Riddle to love his mother:   Voldemort's real intentions for murdering his father was not to give revenge for his mother, Merope, but intended it as a revenge just for himself and just to give way for his horcrux.   Is this theory correct? Or there's other reasons contributing to the fact that Voldemort never loved anyone?


Ubuntu server installation installing SSH

I have a Windows 10 laptop, do I need to install Ubuntu before I can install Ubuntu Server for managing SSH and web hosting?


Can relative speeds be greater than the speed of light?

I am trying to wrap my mind around special relativity and I have these questions:  If I am moving at 70% of the speed of light (relative to the ground) to the right, and my friend moves at 70% of the speed of light (relative to the ground) to the left, are we moving apart at faster than the speed of light?  Does this mean that from my perspective, he is moving away from me at faster than the speed of light?  How about from the perspective of a third party not moving (relative to the ground). Do they see us moving apart at faster than light?


Graph contains a cycle containing at least 4 nodes

There is a finite undirected graph in which the degree of every node is at least 3.   How to prove that this graph contains a cycle containing at least 4 nodes.  No need to prove that a cycle with a chord, only need to show is that it contains a cycle containing at least 4 nodes.


Could you help me to find an arrow symbol I found it in   using as items in blue (at the first page):


How many non congruent trapeziums are possible with the side lengths from {1,3,4,5,6}

I need to find number of mutually non  congruent trapeziums with side lengths from {1,3,4,5,6}.   I know for a trapezium with a,c as non parallel sides the condition for my question is that  $$|a-c|<b+d<a+c$$  But i cant apply it to count the cases. Can someone help in how to get the number of cases?


Setting/finding Android 7 encryption password

I updated the 2016 firmware on my Lenovo P2 to Android 7 (I think my carrier decided that their own app was more important than security updates).  Now that I wanted to put the TWRP recovery onto the phone instead of the stock one, I find out that the phone is encrypted, which it wasn't before. I have not asked for it (it appears Google does this by default now for Android 7) and I have never entered a password explicitly for encryption.  However, TWRP asks for a password for decryption purposes, I believe.  I use fingerprint/PIN as screen lock.  and others suggest it should be the PIN, however while that works fine for a normal startup of the phone, that doesn't work in TWRP.  How would I find or set the right password to use (doubting there is a default password!)?


I'm an astrophysics student and I've been researching this topic and there is one point that keeps eluding me.  How did the scientific community realize that there had to be  in the Universe?


How to check in javascript how many direct properties object has? I want to know amount of direct properties in one object, not in prototypes chain. Is there any method to do so?


Serebii says that (probably) the only  in ORAS are Kyogre, Groudon, Rayquaza and Deoxys. This means that Reshiram and Zekrom, that were shiny locked in BW/B2W2, now can be found shiny.    Can anyone prove this? I'd like to know if it's true before waste hours in softresetting.


I joined Area 51 earlier today. I find out very interesting to track proposed forums, vote on example questions, etc.  When I think of a downloaded Android app, I expect nearly all functionality... Which would include Area 51 sample question posting, sharing proposal links, commenting to revise sample questions, etc.  The layout for Area 51 is unique, but I feel that it could be easily translated into the Android app, especially for the future tablet version. You can view proposals by tag (or category). You can easily flag silly sample Qs or comments.


The probability of a student speaking spanish is $30\%$. If we select $3$, what are the chances of at least one of them speaking Spanish?

In a school the probability of a student speaking Spanish is $30\%$. If we select $3$ random students, what are the chances of at least one of them speaking Spanish?   So, I saw this question and tried to solve it, seemed like an easy question but I was wrong and still not sure why.  Apparently the correct answer is $65.7\%$ ($100\% - 70\% \cdot 70\% \cdot 70\%$)  My first attempt at solving I figured $90\% = 3 \cdot 30\%$ (I just need $1$ student to know spanish, and I have $3$ "chances").  What is the corrent approach for this?  I created this question but for some reason it created in a non-registered account, sorry for the duplicate.  Also, I used the word odds, but I meant probability, english is not my first language and the question was written in portuguese. Sorry for confusion


What are SPF records, and how do I configure them?

This is a  about setting up .     I have an office with many computers that share a single external ip (I'm unsure if the address is static or dynamic). Each computer connects to our mail server via IMAP using outlook. Email is sent and received by those computers, and some users send and receive email on their mobile phones as well.  I am using  to generate an SPF record and I'm unsure about some of the fields in the wizard, specifically:   Enter any other domains who may send or relay mail for this domain Enter any IP addresses in CIDR format for netblocks that originate or relay mail for this domain Enter any other hosts which can send or relay mail for this domain How stringent should SPF-aware MTA's treat this?   the first few questions i'm fairly certain about... hope i have given enough info.


How can I set up my Laptop as an extended second screen for my PC?

I do general programming support and operate with a screensharing software "GoTo Meeting". It'd really help my situation if I could have 2 monitors connected to my workstation (since all my work is recorded). My Dell Inspiron tower has one RGB and one HDMI port, which isn't a bad thing, but the monitor I have only supports RGB, which means that I need something to connect the HDMI to. Having one screen dedicated to my screenshare software would really boost my efficiency, but budgets don't give me the option to go and purchase another monitor, and I have no choice but to use this Inspiron tower for the office.  The only things I have that have an HDMI slot are an HP laptop and a Gateway laptop, both of which I have just reformated to Factory. Both are on Windows 7 Home, and the tower itself is Win8.  Is there a way I can set up an extension of my main Tower to support one of these laptops as the other screen?  I did some other checks around here but the various questions asked seem to be from years ago, and I'm hoping that options are available since then.


Shame the previous thread on this was closed. A lot of my work entails getting stuff right and being able to justify it but like many on this previous thread  point out it's kind of a)arbitrary decisions (e.g. a sub at PC World) or b)a slippage/usage-frequency thing which defines spelling of this and that.  While the word cat is pretty fixed, we're on a spectrum of usage with a lot of tech terms. In my view Wi-Fi is not a trademark and even by now people talk about doing the hoovering when Hoover is a trademarked product. So "Where are we at with Wi-FI, WiFi, wi-fi, wifi?" is my question to folk here.


Picking coefficient in Inverse Distance Weighted method of QGIS?

I'm using QGIS 1.8.0 to interpolate weather data. This is, I have a weather station located in say, A and C. With the Inverted Distance Weighting or Triangular Interpolation methods, I can know/interpolate information in B. When using the IDW method, I have to choose a coefficient.   Does anyone know in which range the coefficients should be?   Say from 1 to 10 or .1 to .99 or 100 to 1000?   Any ideas?


Why is $ \mathrm{Frac} ( A / \mathfrak{p} ) = A_{\mathfrak{p}} / \mathfrak{p} A_{\mathfrak{p}} $?

$ A $ is a commutative ring, $ \mathfrak{p} \in \mathrm{Spec} A $, $ A_{\mathfrak{p}} = ( A \backslash \mathfrak{p} )^{-1} A $, $ \mathrm{Frac} ( A / \mathfrak{p} )$ is the field of fractions of $ A / \mathfrak{p} $.      I would like to know why is  $ \mathrm{Frac} ( A / \mathfrak{p} ) = A_{\mathfrak{p}} / \mathfrak{p} A_{\mathfrak{p}} $ ?    Thanks a lot.


I must find the residues of $z^2\sin(\frac{1}{z})$ at $z = 0$.  Since $z = 0$ seems to be an Essential Singularity, i'm not sure how I can continue to find the residue of the function. Usually I am able to apply the Taylor Series and then find the $z^{-1}$ coefficient, but in this case I do not get a $z^{-1}$ term.


Calculate this integral, $\int_0^{\infty}\frac{\ln^2x}{1+x^2}dx$

$\displaystyle\int_0^{\infty}\dfrac{\ln^2x}{1+x^2}dx$  $x=\arctan\alpha$  $dx=\dfrac{1}{1+\alpha^2}d\alpha$  and try a lot items, but didnt arrived anywhere.


I have to prove that if a nonempty subset $S$ of $\mathbb{R}^n$ is both open and closed, then $S=\mathbb{R}^n$  Does anyone have an idea I am new to this stuff.


How to prevent an object with a null value from being pushed into a stack?

Just as the title suggests, I'm trying to create a card game here but am currently having trouble with a discard function in which, I select a card from my hand and discard it into a stack. Each card has a value from 0 to 12. But the problem is that at times I get a NullPointerException from getting a card with a null value (which should not exist). I've traced the code and determined that somehow. On top of discarding a normal card, a card with a null value is discarded as well, given that after testing some code to print the card values of each card in the stack (from top to bottom), the exception appears after the card I've discarded is printed. Here's the action listener or a button that I click in order to discard a card: pDiscard1.addActionListener(new ActionListener() {                     @Override                     public void actionPerformed(ActionEvent e) {                         try {                             if (cardSelected && (dPile == null && sPile == null)) {                                 game.pdc[0].discard(card);                                 for (int i = 0; i < game.playerHand.size(); i++) {                                     if (game.playerHand.get(i) == card) {                                         game.playerHand.remove(i);                                         break;                                     }                                 }                                  cardSelected = false;                                 discarded = true;                                 display();                         } catch (Exception exception) {                             System.out.println("The card you have attempted to discard is invalid. You can only discard cards from your hand.");                         }                     }                 });  And down here is the code for the discard: void discard(SkipBoCard card) {         dPile.push(card);     }  If any other information is needed, please do let me know. Any help regarding this problem would be greatly appreciated. EDIT: Here's the stack trace: Exception in thread "main" java.lang.NullPointerException     at SkipBo.SkipBoGUI.display(SkipBoGUI.java:618)     at SkipBo.SkipBoGUI.<init>(SkipBoGUI.java:507)     at SkipBo.SkipBoMain.main(SkipBoMain.java:5)  Line 507 is the call for the display method (which updates the visuals of the GUI), and 618 is a part of an if-statement that changes the text of the cards in the buttons/panels for a card. This is because it doesn't have a try-catch exception handler because I'm try to get to the bottom of why this problem is happening (thus far no luck). This information certainly feels like a dead end, but I hope this can help in any way.


Is there any way to run a program that uses a dos executable file on a desktop? I have one program that is a must for my work and I cannot find anything comparable in Ubuntu aps.


How to finish this argument showing preimage of maximal ideal is maximal under surjective map.

Let $f: R \to S$ be a surjective ring homomorphism. Let $M \subset S$ be maximal, and let $f^{-1}(M) \subset I$ for some ideal $I \subset R$. Then $M=f(f^{-1}(M)) \subset f(I)$ since $f$ is surjective. Since $M$ is maximal in $S$, then either $f(I)=M$ or $f(I)=S$. If $f(I)=M$, then $I \subset f^{-1}(f(I)) =f^{-1}(M)$, hence $I=f^{-1}(M)$.  Now, I'm having trouble showing that if $f(I)=S$, then $I=R$.


What is a strong way to protect against sql injection for a classic asp app?  FYI I am using it with an access DB.  (I didnt write the app)


I'm trying to create a new field, but Drupal came up with the well-known error:     The machine-readable name is already in use. It must be unique   I'm sure that the field doesn't exist anymore (I checked the fields' list and it doesn't show up). I want to use that specific machine name because I already have developed some functions that are using that name.  So I guess the name is still saved in the database, there is a way to delete it without screw everything up?  Thank you for your time!