Groups and Symmetries Question on permutations and cycles

Let a=(123)(456) be in S10. If H is a cyclic subgroup of S10 and a is in H, what are all the possible orders of H?  My attempt: The order of a is 3 and the order of S10 is 10!. So we must find the greatest order b such that b^k = a for some k and then order of b <= order of H <= order of S10. Also H is cyclic so it can only take on even orders. Is this right? Please help! Thanks


Clustering geographical data based on point location and associated point values

Given data points with longitude, latitude, and a third property value of this point. How can I cluster points into groups (geographical sub-regions) based on the property value? I searched by google and figured out that this problem seems to be called "spatial constrained clustering" or "regionalizing". However, I am not familiar with handling geographical data and haven't get an idea about what kind of algorithms are good, and which python/R packages are good for this task.  To give a more intuitive idea about what I want, let's say my data scatter plots are as following:   So each dot is a point, x is longitude, y is latitude, and colormap shows whether the value is big or small. I want to divide those points into sub regions/groups/clusters based on location and similarity of values. Like the following (it is not exactly what I want, just to show a intuitive idea.):   So how can I achieve this?


Edit: it's still problematic because the names aren't very descriptive. Based on past values (from Windows) I can sort of deduce what is what, but it's still uncertain. The problem is that the reading names are not descriptive. I'll open a new question for that though.  I'm trying to read my temprature sensor values using Xsensors and Psensor, but both programs only show a single value - what I suspect to be the CPU core temperature.  Here's a screenshot to illustrate:    I would like to also see:   GPU temperature CPU socket temperature disk drives temperatures fan speeds if possible etc - everything programs like HWMonitor can show on Windows basically   How can I achieve that?


Show that $n! ≥ 2^{n-1}$ is true by induction for n being a positive integer

I start off by doing the base case: Base Case: Let P(n) be $n! \ge 2^{n-1}$. Then $P(1)$ will be: $$ 1! \ge 2^0  $$ $$ 1 \ge 1 $$ So the base case is true. Induction: I assume $P(k)$ is true for some arbitrary positive integer $k$. Now I need to show that $P(k+1)$ is true. So assuming $k! \ge 2^{k-1} $ is true, I need to show that $(k+1)! \ge 2^{(k+1)-1} $ is true. $$ 2^{(k+1)-1} = 2 \cdot  2^{k-1} $$ $$\le 2 \cdot k! \tag{By inductive hypothesis}$$ My question So I have solved this to this point but I don't really know where to take it from here. I would appreciate any help on completing this proof.


Have you all solve importing Z point from dxf to QGIS?

I have read all the answer about importing dxf to QGIS, but I still not understand yet.  Does anyone have a video link (youtube or another) that show me step by step to export dxf with Z point to QGIS?


Add an application to the command search path in csh

Recently, I have installed an application (gnuplot) under user directory (/home/usr/bin). I want to run the application whenever I type 'gnuplot' in any directory. What could I do?  I tried to set the path in ~/.cshrc by  setenv gnuplot /home/usr/bin/gnuplot   but it doesn't work. It reports "command not found" as I type gnuplot in the terminal.


Windows server 2012 Essential R2 trial activation

I've installed Windows Server 2012 Essentials R2 on my server. Then I've bought an OEM licence to add on this server.  I've tried to convert my trial to "full licenced" with my key, but the system always refuse my key :(  I've seen on Microsoft Web site that WS2012 Essentials trial can be converted to full version with the slmgr.vbs script, but it also refuses it !  I've also read somewhere that the server can't be a Domain Controller to be activated, but it seems that we can't remove the DC role on WS2012 Essentials R2 ?  Do someone have a trick ?  Regards  Edit : This is not a question about licensing, but a question about Activating a licence that I already own : The procedure given by microsoft gives me troubles, I ask for help about commands to make my server accepting my licence.


"He is having a cell phone" - is wrong.   Instead we use:     "He has a cell phone".    However, both A and B below are correct:     A) "We are having a class"       B) "We have a class"     Why?


Converting characters in string to int in c# to pairs of digits from two strings

I want to take two string input from user in c#, and than convert them to integer by their position in array and then add them. My code is the one below.          string a = Console.ReadLine();         string b = Console.ReadLine();         int i,c,d,j;         for (i=a.Length-1;i>=0;i--)         {             c = Convert.ToInt32(a[i]);             d = Convert.ToInt32(b[i]);             j = c + d;             Console.WriteLine("{0} ",j);             Console.ReadKey();         }   This code is showing wrong output such as "99 99" for input "12 21".  I wanted to add c+d then put the sum in j. Ultimately I want to write a code for big sum problem. Where I am making mistakes?  Expected: for strings "12" and "34" output to be "46" (1+3 and 2+4).


the ubuntu 16.04 software center doesn't work

when I open the Ubuntu software centre it intermediately closes   What can I do??


What logical fallacy considers a personal experience to be common place

While my wife and I were discussing the news a few days ago I stated  that an argument expressed (in a news article, not by my wife) was a fallacy -- but I've been unable to put a name to it.  Basically, it is when a person experiences some experience (personally or thru acquaintance), and thus considers it a common experience because they have experienced it.


Unexpected output of expanded value of counter in aux file, when using \DeclareCaptionFormat

I'm trying to circumvent the message prompt by the caption package, saying that an unknown class or package is messing with the \caption macro. I'm required to expand a value of a counter to then write to the aux file within the definition of \caption.  My original approach was something like this (this is an extremely mutilated version of the real thing):  \documentclass{article} \usepackage{caption} \usepackage{letltxmacro} \makeatletter \def\cm@namedef{\global\@namedef} \newcount\caption@counter@i \caption@counter@i\z@ \LetLtxMacro{\oldcaption}{\caption} \def\caption#1{% \global\advance\caption@counter@i\@ne   \ifnum\caption@counter@i>2     \global\caption@counter@i=\@ne \fi \savecaptionposition \oldcaption{#1}}% \captionsetup{font={footnotesize}}% \def\savecaptionposition{% \expandafter\protected@write \expandafter\@auxout \expandafter{% \expandafter}% \expandafter{% \expandafter\string \expandafter\cm@namedef \expandafter{% \the\caption@counter@i% }{}}} \makeatother  \begin{document} \begin{figure} a4a4a4a4 \caption{Test} \end{figure} \begin{figure} a4a4a4a4 \caption{Test} \end{figure} \end{document}   Looking at the aux file, the output (on TL2014, maximum updated installation) is  \relax  \cm@namedef{1}{} \@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces Test}}{1}} \cm@namedef{2}{} \@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Test}}{1}}   (Pay attention to the values 1 and 2 in inside the first argument of \cm@namedef.  Perhaps I was naive to think that this should yield the exact same output:  \documentclass{article} \usepackage{caption} \usepackage{letltxmacro} \makeatletter \def\cm@namedef{\global\@namedef} \newcount\caption@counter@i \caption@counter@i\z@ \DeclareCaptionFormat{cmfix}{% \global\advance\caption@counter@i\@ne   \ifnum\caption@counter@i>2     \global\caption@counter@i=\@ne \fi \savecaptionposition #1#2#3}% \captionsetup{format={cmfix},font={footnotesize}}% \def\savecaptionposition{% \expandafter\protected@write \expandafter\@auxout \expandafter{% \expandafter}% \expandafter{% \expandafter\string \expandafter\cm@namedef \expandafter{% \the\caption@counter@i% }{}}} \makeatother  \begin{document} \begin{figure} a4a4a4a4 \caption{Test} \end{figure} \begin{figure} a4a4a4a4 \caption{Test} \end{figure} \end{document}   It doesn't: the output of the aux file is as follows...  \relax  \@writefile{lof}{\contentsline {figure}{\numberline {1}{\ignorespaces Test\relax }}{1}} \cm@namedef{2}{} \@writefile{lof}{\contentsline {figure}{\numberline {2}{\ignorespaces Test\relax }}{1}} \cm@namedef{2}{}   In this case the expanded value of the counter is 2 in both cases.  Why does this happen, and how can I mimic the same behaviour as case 1?  Here's an MWE in which you can quickly see the difference:  \documentclass{article} \usepackage{caption} \usepackage{letltxmacro} \makeatletter \def\cm@namedef{\global\@namedef} \newcount\caption@counter@i \caption@counter@i\z@ \LetLtxMacro{\oldcaption}{\caption} \DeclareCaptionFormat{cmfix}{% uncomment this line %\def\caption#1{% comment this line \global\advance\caption@counter@i\@ne   \ifnum\caption@counter@i>2     \global\caption@counter@i=\@ne \fi \savecaptionposition %\oldcaption{#1}}% comment this line #1#2#3}% uncomment this line \captionsetup{format={cmfix},font={footnotesize}}% uncomment this line %\captionsetup{font={footnotesize}}% comment this line \def\savecaptionposition{% \typeout{[SCP] Counter I is \the\caption@counter@i}% \expandafter\protected@write \expandafter\@auxout \expandafter{% \expandafter}% \expandafter{% \expandafter\string \expandafter\cm@namedef \expandafter{% \the\caption@counter@i% }{}}} \makeatother  \begin{document} \begin{figure} a4a4a4a4 \caption{Test} \end{figure} \begin{figure} a4a4a4a4 \caption{Test} \end{figure} \end{document}


Windows Explorer can no longer make new folders

I (actually, a very unfortunate friend of mine)   can no longer create new folders from the Windows Explorer program. (It is important to note that mkdir and friends still work.) I have no idea how this came to be, but my friend denies any system-wide changes around the time it started.  How might I go about adding it back in as it would normally be?  (Note also that other context menu options remain—the 'new folder' one simply is not among them.)


Prove that if $3\mid n^2 $ then $3\mid n $.

$n \in \mathbb{N}$  Prove that if  $3\mid n^2 $ then $3\mid n $   I want to prove this in a accepted formal way, I thought about the fact that every integer can be written as multiplication of prime numbers. and if we raise this integer to the power two we will get multiples of each prime. $3\mid n^2 $, it means that this $"3"$ must have been in $"n"$ before raising it to the power. I am going to the right direction? and if yes, can someone hint how can I write it formally?


Hi is it possible to make a search box which are searching only for some specific content.  it should be a search box that should look at titel, ingrediensliste, body, and who have made it.


There's a question in my Olympiad questions book which I can't seem to solve:     You have the option to throw a die up to three times.  You will earn   the face value of the die.  You have the option to stop after each   throw and walk away with the money earned. The earnings are not additive. What is the expected payoff of this game?   I found a solution  but I don't understand it.


How would you prove that $$n^{\gamma} = m^{\gamma}$$ for every limit ordinal $\gamma$ and $n,m$ finite ordinals?   It's a rather short solution problem, but I can't construct any slick answer for it. I know very little about ordinal exponentiation, just that $\alpha^{\beta +1} = \alpha^{\beta}\cdot\alpha$ and that if there's a limit ordinal in the exponent we take the $\sup$.


Does anyone know how to add an admin menu separator? I found  but it did not help.   Any ideas?


Is it considered bad practice to use non-standard HTML attributes?

I find it very convenient to set arbitary attributes like:  ...   And in JavaScript:  var soId = $selectofA.attr('stackoverflowId'); //jQuery   Is it a good practice at all? I've never had a problem with this yet.


How java references work when passing method parameters

public void synchronized method1(Class_Instance_Variables instanceVar, int classprimitive) public void method2(Class_Instance_Variables instanceVar, int classprimitive)   When passing parameters to method does java creates fresh reference to the methods or  does it use existing reference to pass to the methods ?   Thread-1 get the lock of synchronized method1 and pass "class instance variable" and class instance primitive variable. Thread-2 pass method2 pass same "class instance variable" and class instance primitive variable.  How the references work in this case ? Does it create a new reference for each passing?


The word "References" does not appear before the references which I entered in my paper. The packages I am using are:  \documentclass[final,times,1p,leqno,11pt]{elsarticle} \usepackage[latin1]{inputenc} \usepackage{enumerate} \usepackage{amsfonts} \usepackage{amsmath} \usepackage{amsthm} \usepackage{amssymb} \usepackage{latexsym} \usepackage{multicol} \usepackage{verbatim} \usepackage{amscd} \usepackage{mathrsfs} \usepackage[usenames]{color} \usepackage[all]{xy}   What is the reason of this issue?


When I get the , I used to open the , but initially it shows the duplicate list, which makes me confusing and once I refreshed the page it render correctly. It happening only when the reputation changes.     another screenshots


I am using Ubuntu 15.10, I installed systems updates, Now the system freezes, Nothing works, Not keyboard nor mouse. I have to turn off laptop by holding the power ON/OFF key.  What should i do ?


It's clear that the evolved form of Pokemon have a far higher CP cap (and it looks like minimum too) but it would also seem there is a difference between different Pokemon.   For example I have an Oddish at 184 CP which is at 50% of it's cap, and I also have a Ratata at 185 CP but it is far closer to its cap, around 90%.  Which Pokemon have the highest CP caps?


I tried to fix my hard drive using Ubuntu but I encountered an error message and didn't know how to proceed. I need to fix my bad sectors   fsck /dev/sdb   fsck from util-linux 2.20.1   e2fsck 1.42.5 (29-Jul-2012)   fsck.ext2: Permission denied while trying to open /dev/sdb   You must have r/w access to the filesystem or be root


How to wget a file to a remote machine over SSH?

I'd like to basically pipe a wget command to a file on a remote server over SSH. How can I do this? I know I could simply ssh into the server and have it download the file, but I'd much rather use the local machine to download it and send it.


Troubleshooting "program does not contain a static 'Main' method" when it clearly does...?

My MS Visual C# program was compiling and running just fine. I close MS Visual C# to go off and do other things in life.  I reopen it and (before doing anything else) go to "Publish" my program and get the following error message:     Program C:\myprogram.exe does not contain a static 'Main' method suitable for an entry point   Huh?  Yes it does... and it was all working 15 min earlier.  Sure, I can believe that I accidentally hit something or done something before I closed it up... but what?  How do I troubleshoot this?    My Program.cs file looks like this:  using System; using System.Collections.Generic; using System.Linq; using System.Windows.Forms; using System.Threading;  namespace SimpleAIMLEditor {     static class Program     {         [STAThread]         static void Main()         {             Application.EnableVisualStyles();             Application.SetCompatibleTextRenderingDefault(false);              Application.Run(new mainSAEForm());         }     } }   ...and there are some comments in there.    There are no other errors.  Help?


Intermediate value property problem and continuous function

How to prove that a strictly increasing function $f:[a, b]\rightarrow \mathbb{R}$ which has the intermediate value property is continuous on $[a, b]$.


How to interpret the margin of error in a poll?

Recently the media reported on a political poll that stated that "46% of Republican voters in Mississippi think that interracial marriage should be illegal".  One example story (of many around the 'net) is this one from the NY Daily News: .  From that article:     A survey conducted last month shows 46% of GOP voters in the state   believe interracial marriage should be illegal - a plurality of the   people questioned   Given that I know many people in interracial marriages (including in my own family) I was motivated to track down the full story rather than fall to the obvious hysteria.  I located the press release on the poll from Public Policy Polling  (PDF)  which has:     46% of these hardcore Republican voters believe interracial marriage   should be illegal, while 40% think it should be legal. With Barbour   included, Huckabee gets more support (22%) from the former than the   latter (15%), as does Palin (13-6). The support for Bachmann (10-2),   Gingrich (13-8), and Pawlenty (4-1) works the opposite way.   And at the end of the first page they state:     PPP surveyed 400 usual Mississippi Republican primary voters from   March 24th to 27th. The survey’s margin of error is +/-4.9%.   Now what I don't understand is how to interpret the results especially the margin of error value.    From the raw numbers, 46% (~50%) of 400 voters is 200 voters who responded who think that interracial marriages should be illegal.  But from stats of Mississippi in the 2008 Federal election, McCain polled about 725,000 Republican votes (to Obamas 556,000). My gut feeling is that you can't extrapolate that 46% number to the other 724,600 Republican voters and still retain a 5% margin of error.  So is the media misrepresenting the numbers (really? the media would do that?!?!?!) Or are there statistics at work that I don't understand?  Thanks for your help!


How to create a picturebox of large size(20000,20000) in C#?

I am trying to create a picturebox of large size. I am able to create and draw Bitmap of size upto 8500x8500. But when I clear it and load another Bitmap of same size, it shows OutofMemoryException.  Following is the code snippet:  pictureBox_MouseMove() {     //Draw some lines... }  buttonClear_Click() {      Bitmap new_image = new Bitmap(8500,8500); // OutofMemoryException }   I would also like to know how to allocate memory to these objects.  Thanks in advance.


How do I decode data when I don't know the encoding

I'm recieving data using an OSC server and the data looks like this:  b'Person0/elements/alpha_absolute\x00,dddd\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00?\xbbP\x128\xe6/\xd4\x00\x00\x00\x00\x00\x00\x00\x00' b'Person0/elements/alpha_absolute\x00,dddd\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00?\xbbOw\x8f\xa7\xac\x10\x00\x00\x00\x00\x00\x00\x00\x00' b'Person0/elements/alpha_absolute\x00,dddd\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00?\xbb\x10\x1f\xf2JN\xed\x00\x00\x00\x00\x00\x00\x00\x00' b'Person0/elements/alpha_absolute\x00,dddd\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00?\xbah[\nY\xe9K\x00\x00\x00\x00\x00\x00\x00\x00' b'Person0/elements/alpha_absolute\x00,dddd\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00?\xb8\x8f\x97\xb1\x04\xc4B\x00\x00\x00\x00\x00\x00\x00\x00'   The data title is: Person0/elements/alpha_absolute and the arguments is: dddd (4 floats)  The rest seems to be encoded. I don't understand how to get the 4 floats I'm supposed to recieve  This is my whole code:  import socket  print('Program Initiated') UDP_IP = "127.0.0.1" UDP_PORT = 6000  sock = socket.socket(socket.AF_INET,  # Internet                  socket.SOCK_DGRAM)  # UDP sock.bind((UDP_IP, UDP_PORT))  while True:     data, addr = sock.recvfrom(2048)  # buffer size is 1024 bytes  if 'alpha' in str(data):     print(data)


Why are savings rates the same as CD rates?

Looking at Ally bank (), a 12-month CD has the same APY as a savings account.  (9-month CDs are an even lower APY).  Money in a CD is locked up for 12-months, with a penalty for early withdrawal.  Money in a Savings can be withdrawn any time, but withdrawals are limited to 6 per statement cycle.  What would be the reason for choosing a CD over a Savings Account?  About the only reason I can think of is the interest rate in a CD is locked in, while it is variable (could go down) in a Savings.  What else am I missing?


How can I register account that I posted a question without registering?

I asked a question on Computer Science Educators Beta without registering and need to register it now. How can I do that?


Are the irrationals + zero an additive group?

Is it true that the only way two irrationals can sum to a rational is if they sum to zero?  Thanks!


I am trying to change the chars of a string one by one with for loop and the segmentation fault occurs in real_A[i]=ciphertext[i];, that's the code to change the chars of the real_A string with the ciphertext. here is my code: string substitution(string plaintext, string ciphertext) {     string real_A="ABCDEFGHIJKLMNOPQRSTUVWXYZ";     string real_a="abcdefghijklmnopqrstuvwxyz";               //change alphabets to ciphertext     for (int i=0,n=strlen(ciphertext);i<n;i++)     {         if (isupper(ciphertext[i]))         {            real_A[i]=ciphertext[i];            real_a[i]=real_A[i+32];         }         else if (islower(ciphertext[i]))         {            real_a[i]=ciphertext[i];            real_A[i]=ciphertext[i-32];      }     for (int i=0,n=strlen(plaintext);i<n;i++)     {         if (isupper(plaintext[i]))         {               //get the ascii num            int letter=plaintext[i]-65;                        plaintext[i]=real_A[letter];         }         else if (islower(ciphertext[i]))         {            int letter=plaintext[i]-97;            plaintext[i]=real_a[letter];         }     }          return plaintext;        }  How do I deal with this bug? I tried to change the string real_A="ABCDEFGHIJKLMNOPQRSTUVWXYZ"; to  string real_A[26]; but it got me more errors.


Scientifi notation in CI vaue - how to present it

I have a question on scientific notation in a calculated CI and how to present it. The value of my CI is: 1.623497e+01. So when I write that out do I say that the CI for that variable is 1.62... or is it 16.23 since the e+ means move the decimal one spot to the left?


Why does the composition of the air does not change with altitude?

Air contains about 78% nitrogen and 21% oxygen independent of altitude (up to 100 km). Why is this? Shouldn't the concentration of nitrogen increase with higher altitudes since nitrogen has a lower density than oxygen?


I have a time series data and I want to calculate p90 percentile.  Because there's a huge amount of data I need to split my calculations somehow.  I was thinking that maybe could calculate the percentile of every day data and then , using that, calculate every month, and then using months, the whole year but  ¿Is this calculation method correct? I think is not, in fact to solve the problem exactly I should use all the data to calculate the year percentile, and every time I get a new data I should recalculate  ¿Do you know how to solve/approximate this problem?  This problem is different from continuous P2 approach because I'm not only interested in the final percentile I want the daily, the monthly, trimestral an anual. For example, if I use P2, when I get the January percentile and continue the calculation with February it is not possible to get the isolated February data isn't? I will get the January-February. It will be great to work somehow with monthly percentiles (for example) to get the annual one.


How to proceed after update.php fails due to memory limit?

Sometimes i have a "Fatal error: Allowed memory size exhausted" on certain drupal installations with low php memory limit during module or core updates. After such an error i regularly increase this value with the help of my webhoster to avoid this for future updates...  But on the drupal side i'm lost a bit. The system report shows no indication that the update has to be done again and doing it manually shows that there's nothing to update. But this process failed before...  How do i find out if something went wrong during the update.php process?


Are "I scream" and "Ice cream" homophones, or do we have another term here?

When two phrases are pronounced alike but have different spelling and meaning, can we call them homophones?  e.g. "ice-cream" and "I scream", "nitrate" and "night rate", "that's tough" and "that stuff".  Or is there another term for them?  What linguistic phenomenon distiguishes these near homophones?  I've checked the putative duplicate at  but it isn't exactly what I'm asking here.


Looking for the name of a short story. It was about an AI submarine that woke up one day and did battle with an invading spaceship that was hiding underwater in preparation to invade the earth. The battle ended with both sub and spaceship being destroyed. The close of the story was one man talking to the other about reactivating the subs that were designed to keep enemy subs away


Calculate the determinant of $A \in Mat_n$

Given matrix $A$  \begin{bmatrix}  a_1b_1+1 &a_1b_2 + 1&...&a_1b_n + 1\\ a_2b_1+1 &a_2b_2 + 1&...&a_2b_n + 1\\ ...&...&...&...\\ a_nb_1+1 &a_nb_2 + 1&...&a_nb_n + 1 \end{bmatrix} Find its determinant.  I was using some properties of $\det$ here.  Suppose we have an arbitrary quadratic $n \times n$ matrix $A$.  Let's denote $A + \alpha$ matrix, where we added $\alpha$ to all elements of matrix $A$. Then $\det(A + \alpha) = \det(A) + \alpha \cdot\sum \limits_{i = 1}^n \sum \limits_{j = 1}^n A_{ij}$, where $A_{ij} = (-1)^{i + j}M_{ij}$.  So I got:  \begin{align} & \det \begin{bmatrix}  a_1b_1+1 &a_1b_2 + 1&...&a_1b_n + 1\\ a_2b_1+1 &a_2b_2 + 1&...&a_2b_n + 1\\ ...&...&...&...\\ a_nb_1 +1 &a_nb_2 + 1&...&a_nb_n + 1 \end{bmatrix} \\ & =  \det \begin{bmatrix}  a_1b_1 &a_1b_2 &...&a_1b_n\\ a_2b_1 &a_2b_2 &...&a_2b_n \\ ...&...&...&...\\ a_nb_1 &a_nb_2 &...&a_nb_n \end{bmatrix} + 1\cdot \sum \limits_{i = 1}^n \sum \limits_{j = 1}^n A_{ij}\ \ \ \ (*), \end{align} where $A$ is matrix without $+ 1$'s.  Then $(*) =  \det \begin{bmatrix}  b_1 &b_2 &...&b_n\\ b_1 &b_2 &...&b_n \\ ...&...&...&...\\ b_1 &b_2 &...&b_n \end{bmatrix} \cdot \prod \limits_{i = 1}^n a_i +  \sum \limits_{i = 1}^n \sum \limits_{j = 1}^n A_{ij} = 0 \cdot  \prod \limits_{i = 1}^n a_i + 0 = 0$, because we have equal strings everywhere.  So, $\det$ of initial matrix is equal to $0$.  Can you please check my result?


My son has 2 devices. Tablet and phone. I gave a limit to 1 hour. And I realized that the limit is assigned to both devices. So in the end he has 2 hours. How can I assign the limit as a sum for all devices?


Suppose G is a finite abelian group with a nontrivial subgroup H contained in every subgroup of G. Show that G is cyclic.

The prompt is from Herstein's Topics in Algebra. The proof is to be done without using the structure theorem for finite abelian groups. I showed that $H$ was cyclic of order $p$ a prime and G was a $p$-group. I then set $|G| = p^n$ and proceeded by induction on n. The case $n=1$ is clear. Then, by induction every proper subgroup of $G$ is cyclic. By the Sylow theorems $G$ therefore contains an element $a$ of order $p^{n-1}$. We have $G = \langle a\rangle \langle b\rangle $, where $b$ is any element of $G$ not in $\langle a\rangle $ (here $\langle a\rangle $ denotes the subgroup generated by $a$). Quotient by $K$, the intersection of $\langle a\rangle $ and $\langle b\rangle $, to see that $G/K$ is isomorphic to $\Bbb{Z}_{p}^{2}$, since $G/K$ is the direct product of two nontrivial cyclic p-groups ($\langle a\rangle /K$ and $\langle b\rangle /K$) and by homomorphism every one of $G/K$'s subgroups is cyclic. Therefore taking the preimage of each of the cyclic subgroups of $G/K$, each of which is a distinct maximal proper subgroup of $G$, $G$ must have $p+1$ distinct subgroups of order $p^{n-1}$. Also, note that since $b$ was an arbitrary element not in $\langle a\rangle $ and $\langle a\rangle /K$ and $\langle b\rangle /K$ have the same number of elements, $\langle a\rangle $ contains every element of order less than $p^{n-1}$. Since $\langle a\rangle $ has a unique subgroup of order $p^m$ where $m<n-1$, $G$ has a unique cyclic subgroup of order $p^m$.   This is as far as I've got so far. Not really sure where to go from here. Any ideas? Let me know if you need more details.


Affordable lenses for nightscape photography (nikon d5300)?

I just bought my first DSLR camera Nikon D5300 and currently I only have the kit lenses. I am looking to get some new ones soon to use them to take pictures of the moon and maybe even the stars. As the options out there are countless, can anyone suggest to me the best price for value sense for this purpose? I am looking for something around £100 or less.   Thanks


If the mass of the Earth is decreasing by sending debris in space, does its angular momentum also decrease?

We are sending huge amount of debris into space from earth, and also very heavy satellites and rockets, then the mass of earth must be decreasing over time. If the mass will decrease, then gravitational attraction between earth and sun must decrease, and its angular momentum must decrease, which would result in greater orbit of earth and earth being cooler over the time, but instead the temperature of earth is increasing, why is it so?


Sums of orders of elements of finite groups

Suppose $G$ is a finite group. Then let’s define $s(G) := \Sigma_{g \in G} ord(g)$ as the sum of orders of all elements of $G$.   My question is:     Suppose $G$ and $H$ are two finite groups, such that $|H| = |G|$ and $s(H) = s(G)$. Does that always mean that $G \cong H$?   This statement seems to be true for groups of order up to $12$  For $1$, $2$, $3$, $5$, $7$ and $11$ this is obvious as there is only one isomorphism class of groups of each of these orders.  For $4$: $$s(C_4)=11$$ $$s(C_2 \times C_2) = 7$$  For $6$: $$s(C_6) = 21$$ $$s(S_3) = 13$$  For $8$: $$s(C_8) = 43$$ $$s(C_4 \times C_2) = 23$$ $$s(C_2\times C_2\times C_2 ) = 15$$ $$s(D_4) = 19$$ $$s(Q_8) = 27$$  For $9$: $$s(C_9) = 61$$ $$s(C_3 \times C_3) = 25$$  For $10$: $$s(C_{10}) = 63$$  $$s(D_5) = 31$$  But is it true in general?


Let $0 < a < b$. Use Riemann sums to compute $$ \int_{a}^{b}x^{-2}\ \mathrm{d}x\ . $$ So far, I have gotten to the step where \begin{align} \int_{a}^{b} x^{-2}\ \mathrm{d}x & = \lim_{n \to \infty}\ \sum_{i = 1}^{n} \left[\left(a + \frac {b - a} {n} \ i\right)^{-2}\left(\frac {b - a} {n}\right)\right] \\[5 mm] & = \lim_{n\to\infty}\left[\frac{b - a}{n}\ \sum_{i = 1}^{n}\left(a + \frac {b - a} {n}\ i\right)^{-2}\ \right]. \end{align} I assume my equation is correct, but I am not sure how to evaluate the sum. I also know how to compute $$ \int_{a}^{b}x^{2} \ \mathrm{d}x\ , $$ but I am not sure how to carry forward the idea (if it is even relevant) to this problem (if it is even relevant). Riemann sums were just covered in my module and I am still trying to get used to it. I would appreciate some help/guidance on this!.


PostgreSQL trouble editing points / lines / polygons in QGIS

I have a problem with postgresql and QGIS :   I can add points/lines/polygons and fillup field   But I can't :   delete points/lines/polygons modify points/lines/polygons (move or modify field)   ex : dbname='Europe' host=localhost port=5432 user='postgres' sslmode=disable key='tid' estimatedmetadata=true srid=900913 type=Point table="public"."planet_osm_point" (way) sql=  QGIS is connected as admin level into database. With pdAdmin III I can do all (create, delete, modify...)  The postgresql database is imported from OSM with osm2pgsql.  On other layer, like .shp, I don't have this issue.  Any idea ?  Config : Ubuntu 14.04 / Posgresql 9.4 / QGIS 2.10


Stuck in grub rescue after I tried to upgrade to Windows 8

So I was using Windows 7 and the latest version of Ubuntu on dual boot. I decided to remove my Ubuntu OS so I deleted my Ubuntu partition in 'windows disk management' and alloted the free space to create a new disk.   After that I tried to upgrade my windows 7 to 8 using the windows upgrade tool. The ISO was downloaded and was installing. After some time when the OS had to restart the computer to complete the remaining progress it got struck in grub rescue.  Nothing is helping me out to get out of it. I can't even access anything. I tried the solution given on some forums Where I change the file system to by set prefix = (hdx,Y)/boot)  But the problem is all my file systems are unknown when I try to open it through the 'ls' command. So no file system is allowing me to boot it to normal mode.


How to enable cut action (and shortcut)?

I am using currently Mac OSX v. 10.9.5 and not being able to cut files or folders is the most stupid thing I have seen in an Operating System, with all respect for this nice OS.   Is there a possibility to enable this shortcut or action?


teamviewer 10, ubuntu 14.04 , connection problem

here's my computer spec:   Ubuntu 14.04 LTS 64 bit always do package updates everyday   I'm installing teamviewer 10 by using gdebi similar to this link:   then there are many errors occur on log file, so I chmod all exe files in /opt/teamviewer/tv_bin$ and hope it's ready for connection  but then I get something like this (on logfile, wine):  fixme:service:scmdatabase_autostart_services Auto-start service L"MountMgr" failed to start: 2 fixme:service:scmdatabase_autostart_services Auto-start service L"PlugPlay" failed to start: 2 fixme:actctx:parse_depend_manifests Could not find dependent assembly L"Microsoft.Windows.Common-Controls" (6.0.0.0) fixme:ole:CoInitializeSecurity ((nil),-1,(nil),(nil),0,3,(nil),0,(nil)) - stub! fixme:heap:HeapSetInformation (nil) 1 (nil) 0 fixme:process:SetProcessDEPPolicy (3): stub fixme:ver:GetCurrentPackageId (0x32f8e4 (nil)): stub fixme:process:SetProcessShutdownParameters (00000100, 00000000): partial stub. fixme:win:EnumDisplayDevicesW ((null),0,0x32d510,0x00000000), stub! fixme:win:EnumDisplayDevicesW (L"\\\\.\\DISPLAY1",0,0x32d858,0x00000000), stub! fixme:win:EnumDisplayDevicesW ((null),1,0x32d510,0x00000000), stub! fixme:module:load_library unsupported flag(s) used (flags: 0x00000060) fixme:module:load_library unsupported flag(s) used (flags: 0x00000060) fixme:module:load_library unsupported flag(s) used (flags: 0x00000060) fixme:module:load_library unsupported flag(s) used (flags: 0x00000060) fixme:resource:GetGuiResources (0xffffffff,0): stub WARNING: QApplication was not created in the main() thread. Unable to load library icui18n "Cannot load library icui18n: (icui18n: cannot open shared object file: No such file or directory)"  fixme:ntdll:NtQueryInformationToken QueryInformationToken( ..., TokenElevation, ...) semi-stub fixme:winhttp:WinHttpDetectAutoProxyConfigUrl discovery via DHCP not supported fixme:bitmap:CreateBitmapIndirect planes = 0 fixme:msg:ChangeWindowMessageFilter 233 00000001 fixme:msg:ChangeWindowMessageFilter 4a 00000001 fixme:msg:ChangeWindowMessageFilter 407 00000001 fixme:msg:ChangeWindowMessageFilter 49 00000001 fixme:bitmap:CreateBitmapIndirect planes = 0 fixme:wtsapi:WTSRegisterSessionNotification Stub 0x1007a 0x00000000 err:ole:marshal_object couldn't get IPSFactory buffer for interface {00000131-0000-0000-c000-000000000046} err:ole:marshal_object couldn't get IPSFactory buffer for interface {00000122-0000-0000-c000-000000000046} err:ole:StdMarshalImpl_MarshalInterface Failed to create ifstub, hres=0x80040155 err:ole:CoMarshalInterface Failed to marshal the interface {00000122-0000-0000-c000-000000000046}, 80040155 fixme:msg:ChangeWindowMessageFilter c058 00000001 fixme:bitmap:CreateBitmapIndirect planes = 0 fixme:nls:GetGeoInfoW -1 4 0x32fc44 3 0 err:secur32:SECUR32_initSchannelSP TLS library not found, SSL connections will fail err:winediag:SECUR32_initNTLMSP ntlm_auth was not found or is outdated. Make sure that ntlm_auth >= 3.0.25 is in your path. Usually, you can find it in the winbind package of your distribution.   it's still not ready for connection.  any idea how to solve this?  I've tried to uninstall and install it again using teamviewer 9, same problem occurs.


I have data in the variable "Result" as below  StaffName   ProjectName    Month      Weeks Venkat      Project1       January    4 Venkat      Project1       February   2 Venkat      Project2       January    3 Kumar       Project1       March      5 Kumar       Project4       December   3   Now I want the Output Like below  StaffName   ProjectName   Jan   Feb  Mar  Dec   Total Venkat       Project1      4     2               6 Venkat       Project2      3                     3 Kumar        Project1                 5          5 Kumar        Project4                      3     3   Please help me if you have any idea


I know this question might be duplicate. I am not able to getting the usage of have had from another answers which is exist in Stackexchange. So I asked this question again.  I have examples.   Ann had a red bike for two years.   Sue has had a red bike for two years.   I had a wonderful bicycle.   I've had many wonderful bicycles.   In his lifetime, Uncle Alex had several red bicycles.   In his lifetime, Grandpa has had several red bicycles.   Explain the difference between 1 and 2, 3 and 4, 5 and 6. It would be better if you will take time to explain my examples.


I need the admin URL wp-admin/ to be something else. This is not for security. It only personal preference.  I've tried many plugins and guide which doesn't seems to work for Wordpress 4.4.2:              The guide on first line above do redirect to correct location after login, but showing white screen instead of admin contents.  Some of the plugins also gave similar result, while the rest just give no difference.


Why are there $|G/G'|$ 1-dimensional representations of $G$?

Let $G'$ be the derived subgroup of a finite group $G$.   We have a correspondence $\{\mathrm{reps \ of \ G/G'}\} \longleftrightarrow \{\mathrm{reps \ of \ G \ with \ kernel \ containing \ G' }\} $  If we restrict to 1-dimensional reps, we get:  $\{\mathrm{1\ dimensional \ reps \ of \ G/G'}\} \longleftrightarrow \{\mathrm{1 \ dimensional \ reps \ of \ G \ with \ kernel \ containing \ G' }\} $  Now my notes say that there are $|G/G'|$ 1-dimensional reps of $G$. Since there are $|G/G'|$ 1-dimensional reps of $G/G'$, this must mean that all 1-dimensional reps of $G$ have kernel containing $G'$. Why is this so?  Thanks


Last night I took a night train from Romania to Hungary. I shared a compartment with another American backpacker (and others.) The border crossing on the Romanian side was normal -- all of our passports were stamped and the border officer recorded our data in his notepad. On the Hungarian side, some sort of commotion broke out further down the train car while we were being processed. The officer who was scanning and stamping our passports left and never came back. As a result, the other American backpacker never had her passport scanned or stamped.  What sort of difficulties might she run into since her passport has not been recorded as entering the schengen zone, nor does she have an extra stamp? What might get options be now, from within Schengen, to get her entrance recorded?  (When I say "scanned", the officers had hand-held devices that read the passport biometrics and I assume, recorded some sort of data somewhere.)


Get the real width and height of an image with JavaScript? (in Safari/Chrome)

I am creating a jQuery plugin.  How do I get the real image width and height with Javascript in Safari?  The following works with Firefox 3, IE7 and Opera 9:  var pic = $("img")  // need to remove these in of case img-element has set width and height pic.removeAttr("width");  pic.removeAttr("height");  var pic_real_width = pic.width(); var pic_real_height = pic.height();   But in Webkit browsers like Safari and Google Chrome values are 0.


Will ubuntu work with 2 in 1 asus ux360ca ultrabook?  Thank you in advance for your help!


How to create Multi-select picklist in .design class for configuring lightning component

*Note: I'm trying to implement "Multi-Select Picklist" in design source for configuring lightning component, Not a Picklist in design source for configuring lightning component. For reference I followed this:   I'm able to create Multi-select picklist with .design class in lightning component with design:attribute, see below screenshots for reference. But when I'm passing datasource for that Multi-select picklist then I'm getting below error.  Error I got is: Failed to save MyComponent.design: Only String attributes may have a datasource in the design file.: Source  here it is multi-select picklist in design source    when I click on that select button, I'm getting Multi-select popup as well like below,     But when I'm pass datasource then I'm getting that below error.  My code is: MyComponent.cmp  <aura:component implements="force:appHostable,flexipage:availableForAllPageTypes">      <aura:attribute name="MyVelues" type="String[]" /> </aura:component>   MyComponent.design  <design:component label="MyComponent">       <design:attribute name="MyVelues" datasource="value1,value2,value3" default="value1" /> </design:component>   the error message is here


I'm a windows 10 user ..and I like to use Ubuntu in windows..so I choose wsl 2 and I don't know nothing about wsl 1 & 2 ..can anyone please help me on this wsl2 and configuration . And also how to run Linux GUI apps on windows using WSL2


Today I had a huge scare accidentally changing my laptop password to a keepass-generated 64-alphadigit string, locking me out of my encrypted homedir. My login password was stored in a keepass file on the encrypted homedir, mounted on a locked desktop which I could not unlock due to the password change. Luckily I have my mount passphrase and was easily able to have ecryptfs-recover-private mount to files on some /tmp-folder.  However, I don't just want to recover my files, also the operational part of my laptop automatically mounting them whenever I login, without accidentally destroying something that could indefinitely remove my access to the files. Hence Try-all and error of commands is not OK, I can easily do something I will regret. I could not find anything on the official ubuntu-page:    How do I reconfigure my encrypted homedir with my operating system and user account to function as before, given that my login-password is gone but my mount passphrase is available? Should I copy all my files to a proxy storage? The latter would be a pain, since I don't have the storage to duplicate my homedir.


Does the rotating charged capacitor (both plates) produce magnetic field? and what about rotating both plates in opposite directions?


Which is faster: less RAM in dual channel mode, or a greater amount of RAM?

So I'm thinking of upgrading the RAM on my computer: currently I have two RAM chips, one 1 GB and one 4 GB.  I'm debating on what's the best way to do the upgrade to get the best performance.  Here's what I have in mind: upgrading my RAM to maximize my performance as best I can.  I was originally thinking of swapping out the 1 GB RAM chip for a 16 GB RAM chip for a total of 20 GB.  However, a few people mentioned that I'd be better off swapping out both chips for two 8 GB chips running in dual channel mode than going with 20 GB total.  This seems a bit odd to me, but I'm more of a software person than a hardware person, not knowing much about how hardware works.  Thus, my question is: which would these options would be faster?  A system with 20 GB, with a 16 GB chip and a 4 GB chip or a system with 16 GB, two 8 GB RAM chips running in dual channel mode.  As far as operating systems go, I'm running Windows 7 64 Bit, although I'm thinking of creating a new partition to run Debian Linux one of these days on my computer.  However, the Windows OS is the one I care about for the most part since it's always going to be the one used the most.


Accidentally deleted icons in /usr/share, how do I get them back?

okay, so tyeing to type "icons" in the /usr/share/ directory, hit the delete key as root, now my icons are gone, all of them, the options for play in totem or the ones on the desktop....all of them, any help?


hello i want to know why when i go on any website and console.log(document.cookie) the console doesn't show all of cookies but when i use an extension called editThisCookie i can see all the cookies and i want to know how to do that in javascript, thank you.  editThisCookie:[    console.log(document.cookie);


Can I blend a layer to the canvas in Photoshop?

Blend modes work great between layers but can I blend to the canvas?  For example, take this image:    It has an orange square on the left and transparent canvas on the right. I then placed a black-to-white gradient in the middle and set it to the multiply blend mode. On the left (over the orange) we can see the gradient essentially fading from fully opaque black to fully transparent, but on the right (over the canvas) we see no change in opacity or blending, it's still the plain black-to-white gradient.  Is there a way to make the right side blend with the canvas so that it's fully opaque black at the top and fully transparent at the bottom?  I know that I could use the gradient tool to solve the issue for this simple example, but often I have more complex artwork to deal with and having the ability to make blacks solid and whites transparent over the canvas would be fantastic! I think of this as blending to the canvas but perhaps there's another name or tool for this?  Fireworks had a filter called  which would get the result I'm after. It would convert your later to gresycale, then anything black would become 100% opaque, anything white became 0% opaque, and all shades of grey would fall somewehere inbetween. I'm looking for an eiquivelant feature in Photoshop!


Will running hydraulic brake levers upside down affect performance

I purchased a pair of tektro draco disc brakes recently. They arrived with the hydraulic lines setup moto style, with the longer line run for the left brake lever and the shorter run for the right brake lever.   I wanted to switch it to have left lever / front brake, right lever / rear brake.  So, I just swapped the levers to the opposite side, but now they point resivoir end down.  The only issue I have with this setup is that i have to loosen the levers and rotate them around the bar to bleed them with the reservoir facing up.    Will this cause any performance issues with braking?


Hosting options for running a daily run python script which creates a CSV file?

I wish to run a Python script that daily pulls in some prices and creates a CSV file from them.  What web hosting and cloud options exist to do this.  The script will only run for literally seconds and the CSV file is very small so not much resources at all. I suppose the problem being the Python setup/installation.   seems an option, but want to pay the least amount for this.  Is it possible to do this with AWS, Azure or another Cloud service and which services would I need?


Show $H_2(M, \mathbb{Z}) = \mathbb{Z^r}$ if $M$ is orientable, $\mathbb{Z^{r-1}} \oplus \mathbb{Z_2}$ if nonorientable

I'm trying to solve this problem from Hatcher 3.3.24.  Let $M$ be a closed connected 3-manifold, and write $H_1(M, \mathbb{Z})$ as $\mathbb{Z^r} \oplus T$ where $T$ is torsion. Show that $H_2(M, \mathbb{Z})$ is $\mathbb{Z^r}$ if $M$ is orientable or $\mathbb{Z^{r-1}} \oplus \mathbb{Z_2}$ if $M$ is not orientable. In particular $r \geq 1$ if $M$ is not orientable. Using exercise 6 construct examples showing there are no other restrictions on the homology groups of closed 3-manifolds. (In the nonorientable case consider the manifold $N$ obtained from $S^2 \times I$ by identifying $S^2 \times \{0\}$ with $S^2 \times \{1\}$ via a reflection of $S^2$.)  I think I've solved the first part, here's my proof:   First note the following theorem: If $M$ is a closed connected and orientable n-manifold then $H_n(M, \mathbb{Z}) = \mathbb{Z}$ and $Tors(H_{n-1}(M, \mathbb{Z})) = 0$. If nonorientable, then $H_n(M, \mathbb{Z}) = 0$, $Tors(H_{n-1}(M, \mathbb{Z})) = \mathbb{Z_2}$.  Now note by Poincare duality and UCT we have that $H_2(M) \cong H^1(M) \cong \mathbb{Z^r} \oplus T_0 \cong \mathbb{Z^r}$.   In the nonorientable case consider the exact sequence:  $0 \longrightarrow H_2(M) \longrightarrow H_1(M) \longrightarrow H_0(M) \longrightarrow 0$  But we know $H_1(M) = \mathbb{Z^r} \oplus Z_2$ from the earlier theorem and $H_0(M) = \mathbb{Z}$.   Therefore $H_2(M) \cong ker(\mathbb{Z^r} \oplus Z_2 \rightarrow \mathbb{Z}) \cong \mathbb{Z^{r-1}} \oplus \mathbb{Z_2}$.   For the rest of the question I'm quite lost.


Number of times the ball bounces back when dropped from a building of height h

I need help in calculating the math behind the below question.     A child plays with a ball on the nth floor of a big building the height of which is known . He lets out the ball. The ball rebounds for example to two-thirds of its height.      His mother looks out of a window that is 1.5 meters from the ground.    How many times will the mother see the ball either falling or bouncing in front of the window     Note    You will admit that the ball can only be seen if the height of the rebouncing ball is stricty greater than the window parameter.   Example: h = 3, bounce = 0.66, window = 1.5, result is 3  What i have learnt is      I know that the ball falls from 27 feet and bounces back up 2/3 of that height, so I multiplied 27 times (2/3) and got 18 feet for the height of the first bounce.       Then, since it went up 18 feet, it fell from 18 feet   for the second bounce and bounced back up 2/3 of 18 feet. A table showing the four bounces:    Bounce 1:  (2/3) * 27 feet =   18 feet Bounce 2:  (2/3) * 18 feet =   12 feet Bounce 3:  (2/3) * 12 feet =    8 feet   I dono from this , how to reach solution ?


Why should a CTE start with a semi-colon?

I was just looking at a post on  where Aaron Bertrand proposes using a CTE instead of a numbers table, which is an elegant way of performing the task at hand.  My question is, why does the first line of the CTE begin with a semi-colon?    ;WITH n AS (SELECT TOP (10000) n FROM    (SELECT n = ROW_NUMBER() OVER     (ORDER BY s1.[object_id])     FROM sys.all_objects AS s1     CROSS JOIN sys.all_objects AS s2   ) AS x ORDER BY n ) SELECT n FROM n ORDER BY n; -- look ma, no gaps!   Is this to ensure the WITH statement does not get parsed into a previous SELECT or something?  I see nothing in SQL Server 2005 BOL about using a semi-colon prior to the WITH.


Unable to open windows 8.1 partitions in Ubuntu 12

This is the error coming. I have shut down windows properly and yet this error comes.  Error mounting /dev/sda7 at /media/harshit/Movies and songs:  Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177" "/dev/sda7" "/media/harshit/Movies and songs"' exited with non-zero exit status 14: The disk contains an unclean file system (0, 0). Metadata kept in Windows cache, refused to mount. Failed to mount '/dev/sda7': Operation not permitted The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the 'ro' mount option.


i'm having problems with footnote position. For example, here in this picture:  The footnote is in the end of page, but sometimes it gets too high, like:  There's something I can do to fix this? I'm pretty new in Latex And sorry for my english, I'm still practicing... haha


How do you expect users to:   Know that a site's meta-site exists (and what it's for)? Find the hyperlink to the meta-site?   I know it exists, of course, and how to get there; I'm wondering how (or even whether) you expect new or naive users to do that.  I think there isn't a link to Meta from the main site, am I right (except one link in the "list of all 171 Stack Exchange sites" drop-down menu on the toolbar)?  Sometimes I tell people to post a question on Meta instead of on the main site -- I don't realise that they may not know that Meta exists, and that if they do (because they've been there before) they don't know how to get there (because they haven't yet investigated everything on the toolbar).


In indirect speech present perfect tense is back shifted to past perfect tense.  For example -  John said, "I have written a letter." (Direct speech) John said that he had written a letter. (Indirect speech)  But why I see in news articles that the present perfect tense is often not back shifted to past perfect tense ?  For example -  The President said that investigators have conducted hearings on different issues. (Direct speech - President said "The investigators have conducted hearings on different issues"  Why often I see in news articles that present perfect tense is not back shifted to past perfect tense though in almost every book its written present perfect tense is to be converted to past perfect tense in reported speech ? Please advise me on it. Thank You


What word or phrase is like a more negative version of “astonished”?

Is there a better word for the following example than astonished?     I was astonished at the lack of respect Joe showed to his parents.   I’m trying to use the word astonished in a sentence, but I want to convey that I am surprised at a negative outcome.  Here, the lack of respect towards one’s parents is the negative part, but astonished is neutral, not negative.


Guideline for using mesh(bmesh) library in blender

I am a new blender API/addon developer. I am really bad at the mesh(bmesh) library. Do you guys know any guide or tutorial to use mesh library of blender API? the docs of Blender are really useless. I hardly understand it. I need more like a source with visual examples


Insert an emoji inside a string in Delphi 2007

I'm trying to do exactly what the title say, insert an emoji into a string in Delphi 2007, just like the example below :  procedure TForm1.Button1Click(Sender: TObject); var s : string; begin s := 'This is my original string (y)'; s := ansireplacestr(s,'(y)','👍'); showmessage(s); end;   I can even paste the emoji into IDE's code, but in runtime showmessage results in this :  This is my original string ????  Is there a way to achieve this task in Delphi 2007 ? Due to several reasons i can't upgrade Delphi right now.  Someone said my question is solved on this topic :    But this topic just says to use third-party components, without telling exactly how to do it.  EDIT : After suggested, i tried to use the functions pos, delete and insert and a widestring var :  function addEmoji(mystring : widestring) : widestring; var r, aux : widestring; p : integer; begin r := mystring; while pos('(y)',r) > 0 do   begin     aux := r;     p := pos('(y)',aux);     Insert('👍',aux,p);     delete(aux,pos('(y)',aux),3);     r := aux;   end; result := r; end;   But the result is the '(y)' replaced by '????'.


Idiomatic Javascript Coding Style - when to declare functions on the prototype vs inside the function constructor

In Javascript, when I want to declare a 'publicly' accessible function what is the idiomatic approach?  MyObj.prototype.foo = function() {     ... }   or   function MyObj() {   this.foo = function() {      ...    } }   What situations would determine one style over the other?  What are the advantages of one over the other?   Thanks a bunch for the help!


Strange property of polynomial functions. Is this a typo in the book?

There's one Apostol's Exercise that asks to show that if $f : \mathbb{C} \to \mathbb{C}$ is a polynomial function with real coefficients, then $f(z)=f(i)$ for every complex number $z \in \mathbb{C}$. But I'm certain that this is false, because it would be saying that every polyonomial is constant. And indeed, finding a counterexample is pretty straightforward. Let $f(z)=1+z+z^2$ and compute $f(1+i) =2+3i$ and on the other hand $f(i)=i$ which are clearly different.   Since the seccond item of the exercise asks to show that using this fact we can prove that the complex zeroes of $f$ occur at pairs of complex conjugates, I've managed to replace the first question by proving that $f(z)=f(\bar{z})$ for every $z$.  Is my conclusion correct? Is this really a typo?  Thanks very much in advance.


How to allow iOS 7 iPhone to sync? "Trust this computer" appears endlessly

My iPhone 4S won't connect to my computer when running Ubuntu 13.04. The "Trust this computer" prompt just endlessly pops up. Without actually connecting.  Any ideas? Maybe this is just going to be it with iOS 7.


The built in SA login on a server has full access too all databases. Is there a way to have a login, that has read-only access to all databases, current and future databases? So like sa, but with readonly access?


Watching Youtube and listening to music at same time in android phone- Is it possible

How can I watch Youtube video (app) muted as well as listen to music in phone's built in music app in any android phone?  It is not a duplicate of this , I had seen that before. The answer there asks us to watch youtube in browser. but  my question is  watching youtube video in youtube app, while listening to music.   May I know if that is possible?


What is the volume of the solid defined by $x^4+y^4+z^4=1$ enclosed in a box of unit length?

I came across a post on  asking if it was a higher analogue of the Pythagorean theorem.   It made me wonder: if we plot $x^2+y^2+z^2=1$, of course we get a sphere. But if  $x^4+y^4+z^4=1$, we get this solid instead:  $\hskip1.8in$  I know by a result of Elkies that this has infinitely many rational points $x,y,z$. What else is known about this solid?    For one, what is its name?  Also, if we snugly enclose it in a box of unit length, what is its volume?     P.S. For  $x^5+y^5+z^5 = 1$   $\hskip1.8in$


Let $f:A\rightarrow B$ be an epi morphism in an exact category and $g:X\rightarrow B$ be a morphism.  Is there a morphism $h:X\rightarrow A$ such that $g=f\circ  h$?


I would like to search my table having a column of first names and a column of last names.  I currently accept a search term from a field and compare it against both columns, one at a time with       select * from table where first_name like '%$search_term%' or      last_name like '%$search_term%';   This works fine with single word search terms but the result set includes everyone with the name "Larry". But if someone enters a first name then a space, then a last name, I want a narrower search result. I've tried the following without success.         select * from table where first_name like '%$search_term%' or last_name      like '%$search_term%' or concat_ws(' ',first_name,last_name)      like '%$search_term%';   Any advice?  EDIT:  The name I'm testing with is "Larry Smith".  The db stores "Larry" in the "first_name" column, and "Smith" in the "last_name" column.  The data is clean, no extra spaces and the search term is trimmed left and right.  EDIT 2:  I tried Robert Gamble's answer out this morning.  His is very similar to what I was running last night.  I can't explain it, but this morning it works.  The only difference I can think of is that last night I ran the concat function as the third "or" segment of my search query (after looking through first_name and last_name). This morning I ran it as the last segment after looking through the above as well as addresses and business names.    Does running a mysql function at the end of a query work better than in the middle?


How many natural numbers are multiples of both a and b?

The discussion at  suggests that all common multiples of a and b are multiples of $lcm(a,b)$ and this seems to be true. Certainly all multiples of $lcm(a,b)$ are multiples of a and b, but how do I show that there are no others?


Number agreement when using “(s)” for optional plural

I have a question about the following construction and which instance is correct.        Selecting an appropriate study topic(s).   Selecting appropriate study topic(s).      When it is both singular and plural due to the parenthesized optional part, should I use the an because of thinking of what follows as being the singular (that is, study topic)?  Or should I omit the an because of thinking of what of what follows as being in the plural (that is, study topics)?


"I can have a cookie, can't I?"  (Please ignore the double quotes while reading)  What is this type of question called?  Also, is it grammatically correct under American English?


Which Salesforce License is required to use Environment Hub?

Preface: this is no duplicate  This is not a duplicate of this question    and  are two totally different things. Only the question about which license is required for using each of them can be asked for both distinct Hubs. Please don't get confused. I've carefully split up these two questions and the duplicate mark is definitely wrong.  Original Question  Today I've tried to enable Environment Hub for some of our Developers. Environment Hub itself is working only for me as I am using a Salesforce license with the Profile System Administrator.   Since the Devs are not involved in selling activities, we use Plattform Licenses (Force.com) for them.  Now they should be able to spin up and manage SSO for our dev orgs.  I was able to grant them access to the tab and the objects - but not for the Environment Hub App.  Is there any way to allow these licenses to use the environment hub? If not, why such an restriction? It does not make sense to provide them with a Sales Cloud License.


Can users with less reputation be allowed to chat?

This is something I have faced quite recently. Someone very new to Stack Overflow asked a question, but is not able to communicate properly or exactly understand the answers that has been given for his question. He normally clarifies that in comments. But sometimes, it is necessary to have a one-to-one conversation with the one who has given the answer, so that the comments section is not populated with some trivial comments. So, I just felt that it'd be great if the reputation limit for talking in chat is removed.


Consider $b$ - set of the upper triangular matrices, and $n \subset b$ $n$ - of strictly triangular upper matrices (zero diagonal) What form of $b / n$? We already know that $b$ is a subalgebra of $gl (n, F)$ and that n is ideal for b, so: $b / n = \{x + n | x \in b \} $, but, $ x = n_1 + d_1 $ with $ n_1 \in n $ and $ d_1 \in d $, hence $ b / n = \{x + n | x \in b \} = \{(n_1 + d_1) + n  |  n_1 \in n , d_1 \in d \} = \{d_1 + n |  d_1 \in d \} $ is correct?


What are correct places for:   Global environment variables meant to affect all users? User-specific environment variables?


Lyx redefine tabular with tabularx - strange lines

I tried to redefine the tabular that is used as default for tables in Lyx. The reason is, I want to have an option for 'auto line break in cells'. That you can do with tabularx with the argument 'X'. Example:  \usepackage{tabularx} ... \begin{tabularx}{\linewidth}{ r X }     right-aligned foo & long long line of blah blah that will wrap when the table fills the column width\\ \end{tabularx}   The redefinition of tabular I use in Lyx looks like this:  \let\ORIGtabular\tabular \let\ORIGendtabular\endtabular \let\ORIGtabularx\tabularx \renewcommand*{\tabularx}{%   \def\tabular{%     \let\endtabular\ORIGendtabular     \ORIGtabular   }%   \ORIGtabularx } \renewcommand{\tabular}{  \tabularx{\textwidth}} \renewcommand{\endtabular}{\endtabularx}    As result I get the following tables (sample lyx file is attached at the end of the post):    Questions & Problems:   Why are the tables 0.1 and 0.2 wider than it's content? How do I prevent this? How do I set 'X' argument for each cell as default?


What is the best mobile data solution for a short trip in the US?

I'm going on a vacation to the US next month for 2 weeks.  Instead of paying roaming fees, I'd like to buy a new SIM card with a prepaid amount from a local store/carrier. I don't think wifi networks will suffice for my needs.  Is that an easily achievable solution for short-term vacationers? Also, what is the deal with US mobile networks not using the GSM standard?


I really don't know what's going on with the Android app I'm building. At some point on its development, I started getting it breaking as soon as it starts in the emulator, with the message "Foo stopped". Here is the error log, if anyone could help me:  07-05 21:13:30.063    7647-7647/root.fazerumsom E/AndroidRuntime﹕ FATAL EXCEPTION: main Process: root.fazerumsom, PID: 7647 java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{root.fazerumsom/root.fazerumsom.MainActivity}: java.lang.NullPointerException         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2110)         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)         at android.app.ActivityThread.access$800(ActivityThread.java:135)         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)         at android.os.Handler.dispatchMessage(Handler.java:102)         at android.os.Looper.loop(Looper.java:136)         at android.app.ActivityThread.main(ActivityThread.java:5001)         at java.lang.reflect.Method.invokeNative(Native Method)         at java.lang.reflect.Method.invoke(Method.java:515)         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)         at dalvik.system.NativeStart.main(Native Method)  Caused by: java.lang.NullPointerException         at android.content.ContextWrapper.getResources(ContextWrapper.java:89)         at android.view.ContextThemeWrapper.getResources(ContextThemeWrapper.java:78)         at root.fazerumsom.MainActivity.<init>(MainActivity.java:31)         at java.lang.Class.newInstanceImpl(Native Method)         at java.lang.Class.newInstance(Class.java:1208)         at android.app.Instrumentation.newActivity(Instrumentation.java:1061)         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2101)             at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)             at android.app.ActivityThread.access$800(ActivityThread.java:135)             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)             at android.os.Handler.dispatchMessage(Handler.java:102)             at android.os.Looper.loop(Looper.java:136)             at android.app.ActivityThread.main(ActivityThread.java:5001)             at java.lang.reflect.Method.invokeNative(Native Method)             at java.lang.reflect.Method.invoke(Method.java:515)             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)             at dalvik.system.NativeStart.main(Native Method)


How to display network traffic in the terminal?

how to display the actual network traffic (wireless) in a terminal?  Additionally: Is it possible to add this info to the chart of top?


Multinomial logistic regression and interaction

I am running a multinomial logistic regression and have my final model, but now want to check for interactions between my two exposure variables and my independent variables. When I run this, one of my exposure variables is no longer significant, but some of the interactions between the levels of that variable are significant. I was wondering what the rule was for keeping or removing interaction terms in my model. Do I remove the insignificant variables and consequently any interactions involving that variable? All of my variables are categorical and relevant so there is not a question about whether or not insignificant interactions should be included. THANKS!


Tried to fix filesystem type: FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF and failed

Initially, I had dual-booted Ubuntu on my Mac. Several months later, I decided I no longer needed Ubuntu on my Mac so I decided to get rid of it. I attempted to this by using Disk Utility on macOS and erased the partition. It didn't work, only the swap partition was erased.   Afterwards, I've then accessed the Ubuntu version on my Mac, afterward, I found myself no longer able to access the Mac OS.  I found out that my mac partition had the same FFFFFF-FFFF-FFFF-FFFFFFF problem as this post ()  I followed the instructions of the selected answer but now I can boot into neither of the OS (Before at least Linux was still bootable)  The current state of the machine is as the picture below:    My mac is a 2013 MacBook with 252 GB of SSD drive. It was running OS Catilina (the latest).  I'd really like to obtain my macOS back along with the data/files there.


Bash regular expression pattern matching spaces, within double brackets test, using "~=" operator

Simply said, I just can't find a way to match a variable against some pattern containing spaces.  Here is what I expected to work (echo 'ok' string)  item='foobar baz' pat=".+bar baz" if [[ "$item" =~ "$pat" ]] ; then     echo ok fi   Adding/removing quotes around $pat does not seem to make any difference. I get those two erros below:  bash: conditional binary operator expected bash: syntax error near `~='   Could someone please help me pointing out what I am doing wrong here ? Should I put the pattern right away (without any quotes/double quotes, nor variable reference) ? If that is the case, then how can I put spaces in ? (using reg-exp matching, not an alternative)  Thank you !


My friend and i decided to play some Diablo 3. We played for almost 9 hours straight and killed Diablo on the hard difficult. We reached level 41.  We think 9 hours is short for a game like Diablo 3.   Have we missed something? Why are we only level 41? Is there more story?


Getting a crease when using a Mirror Modifier

I'm trying to model a spaceship and I ran into this weird predicament. I'm using a mirror modifier as can be seen and I get this annoying crease:   If I enter edit mode, you can see that the verticies are connected:   And adding mean crease doesn't fix much:   What's a good way to fix it?


Misleading error message when questions list fails to load

I browsed MSE front page a minute ago, and was greeted with the following error message:     It was not possible to perform this tag search at this time due to an unexpected error.   Screenshot:        I did not search for any tags...  Can the message please be changed to something more meaningful?


Let $M$ be a manifold. Prove that $M$ is path connected if and only if $M$ is connected.  My attempt:  ($\Rightarrow$) Let $M \subset \mathbb{R}^n$ be path connected. Every path connected subset of $\mathbb{R}^n$ is connected.  ($ \Leftarrow$) Let $M \subset \mathbb{R}^n$ be connected. I think that the goal here is to show that for any $x,y \in M$, there exists $a,b \in \mathbb{R}$ and a path $\Phi:[a,b] \rightarrow M$ such that $\Phi(a)=x$ and $\Phi(b)=y$.   I know that since $M$ is a manifold, there exists an open neighborhood $U$ around $x,y \in M$. I also know that $M$ contains a diffeomorphism.  Not sure how to put this all together in my proof..


How to start building desktop applications for Ubuntu Desktop?

I am willing to start building some application for Ubuntu distribution of Linux. I am a Java developer and mostly deal with enterprise systems and some small website with PHP in my free time.  I am willing to create some desktop applications for Ubuntu that I feel they are going to be useful but I don't know what programming language and how to it, can someone provide a guide on how to start ?


Composition of two invertible linear maps

Prove or disprove: Let $A,B: {\Bbb R}^n \rightarrow {\Bbb R}^n$ be linear. If $A,B$ are both invertible, then $A\circ B$ is invertible  Can someone explain if this is true or false? I'm trying to come up with examples but I don't know where to start.


I recently installed Ubuntu 20.04 after using 16.04 for a while. I'm trying to install the school's VPN client which needs these 3 packages: libqtcore4, libqtgui4 and libgnome-keyring0. When I try to install with sudo apt install libqtgui4 I get this error Package libqtgui4 is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package 'libqtgui4' has no installation candidate  The other two packages threw similar errors. I manually tried installing packages from copying them over from the 16.04 installation I had with no luck. I tried downloading manually as .deb files but quickly realized there is no end to the dependency chain. Is there a way I can install these packages at all? Or are they not compatible with 20.04?


I run into a problem when I try to solve a question, show $D_{2^{n+1}}/Z(D_{2^{n+1}})\cong D_{2^n}$. Note: $D_n$ is the dihedral group of order 2n. I have shown $D_{2^{n+1}}/Z(D_{2^{n+1}})\cong D_{2^{n+1}}/Z_2$. But I am not sure how to show $D_{2^{n+1}}/Z_2\cong D_{2^n}$ Thank you.


How to solve the equation $(z+1)^7 = z^7$ for all $z$?

Find all $z$ for the equation   $$(z+1)^7 = z^7$$    The different solutions can be unsimplified and both rectangular or exponential. I have the lead that I subsitute the $z+1$ term with a root of unity. Then, I got lost when I looked at that $z^7$. A thorough explanation would be great!


Is there any difference between Present Perfect and Present Perfect Continuous?

I have studied "present perfect" and "present perfect continuous" for a week. I know forms, verb and helping verb I should use when I write them.  For me, they have nearly same definition because I can use them interchangeably in Thai language. (My native language)  For example, the sentences        I have learned English language in the past few weeks.    I have been learning English language in the past few weeks.       have no difference in meaning to me. They both mean "I began learning the English language in the past and I am still learning it"  Can I use them interchangeably in English? Or is there any difference between them? For example, when should I use present perfect but not present perfect continuous?


I am trying to watch HBONow on Ubuntu 16.04LTS on Chrome browser. It is showing the certification video (i.e. PG-13, TV-MA) and then when it tries to load content it's never shows up.  My windows browser is able to load it successfully. What could be the possible solutions?


I want to assemble several cameras, triggered by a single remote. Is this possible? The trigger doesn't have to be wireless, because the cameras will be very near to each other. The cameras need to be very cheap, because I'll be needing 50 of them.


Okay, first things first, I'm very basic when it comes to the field of physics, but I'm very good at coding, and I was wondering if I could simulate an atom.  I know that in order to make such a simulation, I have to understand the mechanics of the four fundamental forces.  Gravity:  $$\ F=\frac{Gm_1m_2}{r^2}$$  Electromagnetism: $$\ F=\frac{k_eq_1q_2}{r^2}$$  But I don't know what the rules are for Strong and Weak Forces.  I'm very aware of the possibility that we don't yet know such formulas, as made clear by several sources, but I also once remember going on a website and seeing someone with a slideshow showing each of the formulas for fundamental forces, some involving summations and undefined variables, but I can't find this website anymore.  If anybody knows the formulas for Strong and or Weak interactions or has verified that these laws aren't yet solved for, please leave answers below.


I am trying to understand an elementary idea in the transpose of a linear operator, namely that if $S \in L_K(U,V)$ and $T \in L_K(V,W)$ for vector spaces $U,V,W$ over a field $K$ that   $(S \circ T)^t = T^t \circ S^t$.   So it seems I should first take a linear form say $g:W^* \rightarrow U^*$ then $(S \circ T)^t (g) = g(S \circ T)$. Here is where I am stuck. Any hints/tips appreciated.


Derive the generating function: $\frac1{(1-x)^3}= \sum_{n=0}^\infty \binom{n+2}{2}x^n$

$$\frac1{(1-x)^3} = \sum_{n=0}^\infty \binom{n+2}2x^n$$  I am not sure how to begin. $$\begin{aligned}\frac1{1-x}&= \sum_{n=0}^{\infty} x^n\\\frac1{(1-x)^2}&=\sum_{n=0}^{\infty} nx^{n-1}\end{aligned}$$ Then you would get: $$\frac{1}{(1-x)^3} = \sum_{n=0}^{\infty} nx^{2n - 1}$$ Which is nowhere near the same...?


Why does the minimum value of $x^x$ equal $1/e$?

The graph of $y=x^x$ looks like this:    As we can see, the graph has a minimum value at a turning point. According to WolframAlpha, this point is at $x=1/e$.  I know that $e$ is the number for exponential growth and $\frac{d}{dx}e^x=e^x$, but these ideas seem unrelated to the fact that the mimum value of $x^x$ is $1/e$. Is this just pure coincidence, or could someone provide an intuitive explanation (i.e. more than just a proof) of why this is?


How to make camera continuously move along the circle path?

In my scene I have a circle (curve) and a camera, attached to it via CTRL+P > follow path.  How can I make the camera continue moving along the circle, after the first loop ends?


Sequence of measurable functions on finite measurable set

I am struggling to solve the following exercise:  Let $E \subset \mathbb R^d$ be finite measurable and $(f_k)_{k \geq 1}:E \to \mathbb R$ be a sequence of measurable functions such that for all $x \in E$, there is $M_x \in \mathbb R_{>0}$:$$ |f_k(x)|\leq M_x, \space \forall k \in \mathbb N$$ Show that for each $\epsilon>0$, there exists $F\subset E$ closed and $M>0$:$$ |E \setminus F| <\epsilon, \space \text{and}\space |f_k(x)|\leq M, \space \forall k \in \mathbb N, \space \forall x \in F$$  I got stuck at some point but this is what I thought of: Let $(E,\mathcal M_{E},m_{E})$, then it is easy to see that $E=\bigcup_{n\geq 1} (\bigcap_{k \geq n} \{x \in E: |f_k(x)|\leq n\})$, note that $E_n= \bigcap_{k \geq n} \{x \in E: |f_k(x)|\leq n\}$ forms an increasing sequence of measurable sets. Then $\emptyset=\bigcap_{n\geq 1} (\bigcup_{k \geq n} \{x \in E: |f_k(x)|>n\})$. Since $m(E)<\infty$, $$0=\lim_{n \to \infty} m((E_n)^c)$$ Given $\epsilon>0$, there is $N: m((E_N)^c)<\dfrac{\epsilon}{2}$. Since $E_N$ is measurable, there exists a closed set $F \subset E_N$ with $\mu(E_N \setminus F)<\dfrac{\epsilon}{2}$. But then $m(E\setminus F)<\epsilon$ and $$|f_k(x)|\leq N, \space \forall x \in F, \space \forall k\geq N$$ I need this to work for all $k \geq 1$, I don't know what to do with the remaining $1,...,N-1$. Any help would be greatly appreciated.


sudo apt autoremove wants to remove a lot of packages, safe to run?

Following on from a reinstall of ubuntu desktop sudo apt install ubuntu-desktop to fix a previous issue with not booting.  and then a reinstall of google chrome  sudo apt remove google-chrome-stable  I got the following output:  Reading package lists... Done Building dependency tree        Reading state information... Done Package 'google-chrome-stable' is not installed, so not removed The following packages were automatically installed and are no longer required:   gconf-service gconf-service-backend gconf2 gconf2-common gnome-panel-data gnome-shell-pomodoro-data gparted-common intltool   libaacs0 libaom0 libaribb24-0 libass9 libavutil56 libbdplus0 libbluray2 libbs2b0 libcodec2-0.9 libegl1-mesa libflite1   libgconf-2-4 libgme0 libgsm1 liblilv-0-0 libmusicbrainz5-2 libmusicbrainz5cc2v5 libmysofa1 libnorm1 libnuma1 libopenmpt0   libpaps0 libpgm-5.2-0 libpostproc55 libpython2-stdlib libpython2.7-minimal libpython2.7-stdlib librubberband2 libserd-0-0   libshine3 libsnappy1v5 libsord-0-0 libsratom-0-0 libssh-gcrypt-4 libswresample3 libswscale5 libvdpau1 libvidstab1.1   libvo-amrwbenc0 libwxbase3.0-0v5 libx265-179 libxcb-xtest0 libxnvctrl0 libxvidcore4 libzmq5 libzvbi-common libzvbi0   mesa-vdpau-drivers paps python-gobject-2 python2 python2-minimal python2.7 python2.7-minimal python3-distutils-extra   python3-levenshtein python3-pyinotify python3-websocket vdpau-driver-all Use 'sudo apt autoremove' to remove them. 0 to upgrade, 0 to newly install, 0 to remove and 5 not to upgrade.   And running sudo apt autoremove gives a warning about removing these packages      The following packages will be REMOVED ...   And the list of packages again. My question is is this safe to run, are these packages neccessary


Unable to resolve custom hostnames in /etc/hosts

I'm running Apache/2.4.41 on Ubuntu 20.04. I'm trying to setup a virtual host. Neither Chrome nor Firefox are able to resolve hostnames specified in /etc/hosts file. Even before setting up the test.dev.conf file at /etc/apache2/sites-available, the browsers are not able to resolve the hostname. I'm trying to add test.dev.  Contents of /etc/hosts  127.0.0.1   localhost 127.0.0.1   test.dev 127.0.1.1   lakeguardians  # The following lines are desirable for IPv6 capable hosts ::1     ip6-localhost ip6-loopback fe00::0 ip6-localnet ff00::0 ip6-mcastprefix ff02::1 ip6-allnodes ff02::2 ip6-allrouters   I'm able to ping the host though. Running the ping -c 5 test.dev gives the following output:  --- test.dev ping statistics --- 5 packets transmitted, 5 received, 0% packet loss, time 4073ms rtt min/avg/max/mdev = 0.041/0.045/0.047/0.002 ms   Contents of /etc/nsswitch.conf  hosts:          files mdns4_minimal [NOTFOUND=return] dns   I've tried restarting apache2 and rebooting the system, but unable to solve the issue.


Is it possible to transfer Minecraft PE worlds to Minecraft PC?

I have a really cool Minecraft PE world, and I would like to also have it on my Computer. Is there a way to move a Minecraft PE world onto the PC Edition?  My tablet is Android and my Computer is Windows 7. Thanks!


Deleted layers still appear while loading project in QGIS?

I'm working on a project where I digitized a few maps (georeferenced) and I also added a couple of csv files. I deleted the raster and cvs layers after I included them into the project as shapefiles but when I re-load the project to continue working on it these phantom layers still appear in the layer panel until the project is actually loaded and ready to work. It doesn't make any problem other than these layers being listed as options to choose, for instance doing interpolation or other spatial options. The problem occurs when I delete the original csv file from the original location, even though it is not visible in the layer panel. If I do that, QGIS closes with error immediately after opening. I cannot move the csv or raster files from the folder they were originally saved because I cannot load the project.    Same thing was discussed in  but the discussion was closed apparently because it was solved, which is not my case. Any clues?  Windows Vista - QGIS Lisboa 1.8.0


Quotient of polynomials, PID but not Euclidean domain?

While trying to look up examples of PIDs that are not Euclidean domains, I found a statement (without reference) on the  page of Wikipedia that  $$\mathbb{R}[X,Y]/(X^2+Y^2+1)$$  is such a ring. After a good deal of searching, I have not been able to find any other (online) reference to this ring.  Can anyone confirm this result? Is there a reference for it (paper, textbook or website)?


Definition of continuity of open balls or delta

I know how to prove the theorem of the following:  A function f is continuous if and only if the preimage of any open set in Y is open in X.  I am wondering how to show that the theorem is equivalent to the two different definitions of continuity of i) open balls and ii) delta epsilon.


Why google insist that I used 30GB of storage?

My whole google drive, with files, consist of only 2.5 GB.  I have no idea what else I should throw away.  Yet google insist I am using 30GB of space.  I wonder if I can see detail where do I use those space  Google claim I uses 30GB more  But the screenshot clearly shows that I am using a mere 3.5 GB. I wonder what I actually used. The google photos is moved somewhere else too and that's at most a few gigabytes. Trash is empty      The duplicated question have no answer.  In fact, I upgraded my storage to 100GB. Guess what? Google still complain that I don't have enough room.


How to recover from freeze while nothing works?

I am using Ubuntu 14.04.2 LTS. Sometimes Ubuntu freezes and i can't do anything anymore.  What can i do to recover from this situation? In windows it was simple i just had to use task manager via alt+ctrl+delete. Is there something like this in Ubuntu? I know that there is xkill and System Monitor in Ubuntu but when Ubuntu freezes i can't use any of them and i can't open terminal and even though i have set a shortcut for xkill but still after freezing happens i can't use xkill. It's like after freezing nothing works.


Should the words "city"/"state"/"province" be capitalized (if not followed by the name of the city)?

When referring to an entity like a government body, should it be capitalized if referring to is by classification(?).  E.g., if I write:     The City of New York requires us to get a building permit.   Certainly "city" should be capitalized.  However, if I'm communicating in a context where everyone should know what city I'm referring to (the one we are in), when I write:     The city requires us to get a building permit.   Should "city" still be capitalized?


How to determine version Intel Management Engine on Linux?

I just heard about the . I'd like to update my firmware, but I don't use Windows/OSX. How can I find out what version of Intel ME I have and how do I update it?


i want to open two (or more) excel windows on different screen (extended displays), But was not able to. I tried few solutions found on Google.


Expired "authentication token" for user with deleted password

The Setup:  1) The user's password was deleted with "passwd -d " command  2) The user has cron jobs running  The Problem: Once every 30 days (default password expiration policy) the cron fails with an error  Authentication token is no longer valid; new one required ERROR: failed to open PAM security session: Success ERROR: cannot set security context   My Questions: Is there a way to prevent this from happening? Why is the authentication token expired for a user with deleted password?


Parabola and a circle touching at the vertex of the parabola

This is a problem I faced during solving my math homework. I asked my math teacher yet she didn't return to me with an answer.I thought I could prove it algebraically but I ended up with too much parameters. So the approach I chose was to try and prove it on a specific parabola. The general problem is- Suppose we have a parabola $$y^2=2px$$ and we want to find a circle that touches the parabola at only one point $ (0,0) $. Also we want that circle to be inside the parabola (so $(0,0)$ will be the only common point of the circle and the parabola). Is it possible? If it is what is the equation of the circle expressed parameterically? Thanks!


compiling tex files with xelatex is insanely slow on my Windows machine

I try to compile a document that is written in Chinese using xelatex. But I find that the compiling speed is insanely slow: after about 1.14 minute, the final pdf file is generated. Here is a MWE:  \documentclass{article} \usepackage{xeCJK} \begin{document}  测试 \end{document}   If I change the Chinese version to English version (e.g., simply replace 「测试」 with "test"), it makes no difference and the compiling time is more or less the same.   If I comment out \usepackage{xeCJK} and compile the English version using pdflatex. The compilation speed is fast (around 1.5 seconds).   How to solve this problem? Ps, I am using a Windows 8.1 machine.


A finite dimensional algebra over a field has only finitely many prime ideals and all of them are maximal

Let $K$ be a field and let $R$ be a $K$-algebra with unity which is finite dimensional as a $K$-vector space. Prove that $R$ has only finitely many prime ideals all of which are maximal. (Hint: Chinese remainder theorem)   My attempt: We have $R \simeq K^n$, for some $n$, as vector spaces. I claim that there are finitely many ideals of $K^n$. Let $I$ be an ideal of $K^n$ and $(a_1, a_2,...,a_n) \in I$. For every entry $a_i$, we have two choices, either $a_i=0$ or not.  So we get $2^n$ many cases, and any case give a particular ideal of $K^n$ which are distinct from others.  Is my proof correct or am I missing some point? If it is true, how can we give a proof by using the Chinese remainder theorem? Thanks!


SQL Server : return multiple values from function

Is there any way to return multiple values from a function? Ideally looking to do something along these lines (I know that syntax is wrong!)  SELECT      1 as test1, 2 as test2, 3 as test3,      fn_result(test1, test2, test3)[0] as result1,      fn_result(test1, test2, test3)[1] as result2,      fn_result(test1, test2, test3)[2] as result3  FUNCTION fn_result(val1, val2, val3)     RETURN (val1 + val2, val2 + val3, val1 + val3)   I have no experience at all with SQL functions so not sure if such a thing can be done.  Thanks


Does this correctly interpret the "$\cong$" between groups as "$=$" between sets?

I was trying to give the wording "isomorphic groups have the same structure" a precise interpretation, at least for the finite order case. A positive answer to my final question would reach the goal, as it would translate a "$\cong$" between groups into a "$=$" between sets.    For $n$ positive integer, let be:   $I_n:=\{1,\dots,n\}$; $G$, $\overline G$ groups of order $n$; $\psi\colon G \rightarrow \overline G$ isomorphism; $f$, $\bar f$ bijections; $\theta$, $\bar \theta$ embeddings; in general, $\varphi^{(\alpha)}$ the isomorphism between symmetric groups on sets of the same cardinality, defined by $\sigma \mapsto (g \mapsto (\alpha\sigma\alpha^{-1})(g))$, where $\alpha$ is a bijection between the sets; $S_n$ the symmetric group of degree $n$.   Visually:  $$ \newcommand{\ra}[1]{\kern-1.5ex\xrightarrow{\ \ #1\ \ }\phantom{}\kern-1.5ex} \newcommand{\ras}[1]{\kern-1.5ex\xrightarrow{\ \ \smash{#1}\ \ }\phantom{}\kern-1.5ex} \newcommand{\da}[1]{\bigg\downarrow\raise.5ex\rlap{\scriptstyle#1}} \begin{array}{c}    I_n     &   &    I_n      \\     \da{f}         &           &     \da{\bar f}          \\    G & \ras{\psi} &    \overline G  \\     \da{\theta}         &           &     \da{\bar \theta}          \\    \operatorname{Sym}(G) & \ras{\varphi^{(\psi)}} &    \operatorname{Sym}(\overline G)  \\     \da{\varphi^{(f)}}         &           &     \da{\varphi^{(\bar f)}}          \\    S_n &  &    S_n  \\ \end{array} $$     Is it $(\varphi^{(f)}\circ\theta)(G)=(\varphi^{(\bar f)}\circ\bar \theta)(\overline G)$?


Continuous on $[a,b]$ and $f'(x)>0$ on $(a,b)$ except for a $c$ in $(a,b)$ then $f$ is strictly increasing

Prove that if $f(x)$ is continuous on $[a, b]$ and $f'(x)>0$ on $(a, b)$ except at a point $c \in (a, b)$ where $f'(c)=0$, then $f$ is strictly increasing on $[a, b]$. I can prove the case without the $c$ using MVT, but not sure how to approach this particular case.


Error getting touch coordinates in android studio

This is the code:  private static Point c; //c.set(1,1); -> error: "cannot resolve symbol set"?? . . .      @Override         public boolean onTouchEvent(MotionEvent event){             switch (event.getAction()){                 case MotionEvent.ACTION_DOWN:                 case MotionEvent.ACTION_MOVE:                     c.set((int)event.getX(),(int)event.getY());             }             return true;         }   When I touch anywhere on the screen the app crashes and I get the following error:  java.lang.NullPointerException: Attempt to invoke virtual method 'void android.graphics.Point.set(int, int)' on a null object reference


I. upgraded to from 17.04 to 17.10 and it crashes every time the computer gets started.  The purple screen is shown with logo and dots and a mouse cursor which cannot be moved. Then the screen changes to black and displays the message about the harddrive that is normally shown quite at the beginning of a normal start. Then there ia some kind of loop. For a second there are shown the lines with the messages of starting procedure and it goes back to the line about the harddrive. That happens in a loop every 8 seconds.  I made a video:


How is this possible? String always size 40 and structure sizeof odd reading

Okay really confused about something here. Two questions.  First question is according to my compiler, string is always a size of 40 bytes. How is this possible when we can have more than 40 characters in a string and each character should be taking up 1 byte?  Second question: If I have a struct containing a string (40bytes) and an integer (4bytes), why is my resulting structure size 48 instead of 44? I can't figure out what is going on here.  Thanks if anyone knows/understands why i'm getting this behavior.      struct Employee //This struct is size 48 for some reason?     {         string name; //String takes up 40 bytes         int ID; //int takes up 4 bytes     };       struct Size8Struct //This struct is size 8 as expected     {         int ID;         int filler;     };       int main() {         cout << sizeof(Size8Struct) << endl; //returns 8 as expected         Employee Jim; Jim.ID=1; Jim.name="Jim";         cout << sizeof(Jim) << endl; //returns 48, why?          string test = "123456789012345678901234567890123456789012345678901234567890 test"; //How is it possible for this string to hold over 40 chars if it is only 40 bytes long?         cout << sizeof(test) << endl;     }


How can I disable Lenovo Y700 shortcuts?

Recently I bought Lenovo Ideapad Y700. I noticed that when I use chrome and want to go back in a tab using backspace it doesn't work and said that I need to use Alt + left key. How can I enable the backsapce key to work for this function?


What is the difference between "a" and "{a}" in set theory?

I am reading Topology by James Munkres and I got the following question:  I understand that a is an element and {a} is a set containing the element a. I can memorize it, but as I reason it I think that I do not have the difference entirely clear in my head.   This is because I thought that a set itself is only defined by the elements it is made of. That is to say, that the set itself it is nothing other than the elements it is made of. Now the only difference I perceive from a and {a} is that the later would content the elements of the  empty set (since it is assumed that the empty set is  a subset of all sets).   If that is not the only difference between both notions, how would you explain it? Again, I can memorize that they are not different and that visually they are not. But I think that I can understand deeper the concept of a set if I get the difference it has with an element very clear. Thanks.


How do you force constructor signatures and static methods?

Is there a way of forcing a (child) class to have constructors with particular signatures or particular static methods in C# or Java?  You can't obviously use interfaces for this, and I know that it will have a limited usage. One instance in which I do find it useful is when you want to enforce some design guideline, for example:  Exceptions They should all have the four canonical constructors, but there is no way to enforce it. You have to rely on a tool like FxCop (C# case) to catch these.  Operators There is no contract that specifies that two classes can be summed (with operator+ in C#)  Is there any design pattern to work around this limitation? What construct could be added to the language to overcome this limitation in future versions of C# or Java?


Using Includes in a Function to show block if included in a Picklist

I'm intending the following: • If the system_picks field includes the text "Medication Dispenser", make the div with the id "ifYesMed" visible. • Otherwise, hide the div "ifYesMed" What am I missing in the code below? <apex:page standardController="Account">   <apex:stylesheet value="{!$Resource.styleforAccountLightningPage}"/>

      Medication Dispenser Device Number:&nbsp;&nbsp;<apex:OutputField value="{!Account.MED_Device_Number__c}"/>

         </apex:page>  Per recommendations, I have updated my function to function showMedNumber (){            if (CONTAINS(Systems_Pick__c, "Medication Dispenser")){             <apex:outputPanel>             document.getElementById("ifYesMed").style.display = "block";             </apex:outputPanel>         } else {             document.getElementById("ifYesMed").style.display = "none";         } }  I'm still not getting the intended results.  Can anyone assist by letting me know how I should change my code exactly? Thank you!


Any experience with spokes breaking on new Trek 720 touring bike

I have a new Trek 720 Touring bike with about 1000 miles and have broken two spokes on the rear tire in the past two weeks and haven't yet added the weight of panniers.  This is a 24 spoke wheel and I'm told Trek doesn't have a 32 spoke wheel for this application.  I'm concerned for when I begin my cross-country touring in another month and adding another 30-35 # over that wheel.  This Trek model is new this year...anyone else out there have similar problems? I've traveled 1000s of miles without broken spokes until now.  Any diagnosis?  NOTE - Trek has issued a recall for this particular wheelset


By counting in two ways, prove that $\sum_{i=0}^n \binom{i}{k} = \binom{n+1}{k+1}$ for all $k,n \ge 0$.

I am thinking that the RHS can be counted as $\binom{n}{k} + \binom{n}{k+1}$. But I don't how the following counting may go.


I get this error message upon installing .  Missing gir1.2-vte-2.90.  Any help appreciated.


Let $G\subseteq\mathbb{C}$ be a domain and $f\colon G\to\mathbb{C}$ holomorphic. Show:     $$ f'=0\mbox{ in }G\Rightarrow f\mbox{ is constant} $$      Cauchy-Riemann: $$ f'(z)=f_x(z)=u_x(x,y)+i v_x(x,y), z=x+iy=0\\ \Leftrightarrow u_x(x,y)=0~\wedge v_x(x,y)=0 $$  and $$ f'(z)=-if_y(z)=-iu_y(x,y)+v_y(x,y)=0\\\Leftrightarrow u_y(x,y)=0~\wedge~v_y(x,y)=0 $$  That means: If one derivates u and v to x, one gets 0, and therfore the x-part of these functions must be constant. The ssame for the y-part of u and v. So u and v are constant and so is then f.  Is that okay?


What is the word for a corollary that follows from a proof?

I know there's a particular word but can not think of it and have been unsuccessful finding it by googling.  I want to say "porium" but that doesn't come up when I google.