Onclick Event - Undefined is not a function

I am trying to have a click event on
 tag of my table that's dynamically generated.  While registering event for 1st time, there is no exception. But Function is not being called if I click on tablerow.  I tried getElementById also, which is even giving extra exception while registering on click event.  Please help.  Below is part of my code:  Script:  $("#empName").on("click", function(){         alert("Hi");     });   HTML:  $(obj).find('#abc tr:last').after("
"+emp+"
"+eventName+"
"+ind+"
"+loc +"
");


how to insert a hyperlink to cite the author's name/year

I have been struggling to provide a hyperlink to the author's name and year I have used in my bibliography file (doc.bib). Does anyone have a MWE to provide in this case or let me know what I am doing wrong? Thank you.  This is the code I have used so far:  doc.bib  @article{abcd:2006a,   author      = "Torben G. Andersen and Tim Bollerslev and                  Peter F. Christoffersen and Francis X.                  Diebold",   title       = "Volatility and correlation forecasting",   chapter     = 15,   pages       = "777--878",   editor      = "Graham Elliott and Clive W. J. Granger and                  Allan Timmermann",   booktitle   = "Handbook of Economic Forecasting,                  Volume~1",   publisher   = "Elsevier",   address     = "Amsterdam",   year        = 2006, }   doc.tex  \documentclass[11pt,a4paper]{article} \usepackage[latin1]{inputenc} \usepackage[left=2cm,right=2cm,top=2cm,bottom=2cm]{geometry} \newcommand{\doc}{F:/Datasets/KLIPS/data/wave_01_13/tex/1.Introduction/final} \usepackage[colorlinks=true,linkcolor=black, citecolor=blue, urlcolor=blue]{hyperref} \usepackage{cite} \begin{document} \section{A} Bla bla \cite{abcd:2006a}.  \bibliographystyle{plainnat} \bibliography{\doc} \end{document}


Can you replace cyclocross (or road bike) handlebars with mountain bike handlebars?

My cyclocross handlebars are really irritating, please help.


Why is manuscript review in mathematics taking so long (over 8 months)?

I  submitted my paper on mathematics to a journal  8 months ago but I have no received any reports or comments yet. I sent an email to the editor asking him about the manuscript, he just replied that it is still under review. What shall I do?


Can i install Ubuntu alongside Windows 10?

I have a Lenovo laptop with Windows 10 on it. Is it possible to install any version of Ubuntu alongside Windows 10?


Getting a package not found exception even after its installed

I am getting below error when I do a ./configure.  configure: error: Package requirements (gio-2.0 >= 0.23.0                        libgcab-1.0 >= 0.1.10                        uuid >= 1.41.3                        libxml-2.0 >= 2.7) were not met:  No package 'libgcab-1.0' found  Consider adjusting the PKG_CONFIG_PATH environment variable if you installed software in a non-standard prefix.  Alternatively, you may set the environment variables WIXL_CFLAGS and WIXL_LIBS to avoid the need to call pkg-config. See the pkg-config man page for more details.   Unlike my previous question (), this time the error is coming even after the module is installed.  sudo apt-cache search libgcab libgcab-1.0-0 - Microsoft Cabinet file manipulation library libgcab-dev - Microsoft Cabinet file manipulation library - development files  sudo apt-get install libgcab-1.0-0 Reading package lists... Done Building dependency tree         Reading state information... Done libgcab-1.0-0:i386 is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 120 not upgraded.  sudo apt-get install libgcab-dev Reading package lists... Done Building dependency tree        Reading state information... Done libgcab-dev:i386 is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 120 not upgraded.   What can be the problem causing this error?  Edit  apt-cache policy libgcab.* N: Unable to locate package libgcab.* N: Couldn't find any package by regex 'libgcab.*'  grep "universe" /etc/apt/sources.list ## team. Also, please note that software in universe WILL NOT receive any deb http://us.archive.ubuntu.com/ubuntu/ trusty universe deb-src http://us.archive.ubuntu.com/ubuntu/ trusty universe deb http://us.archive.ubuntu.com/ubuntu/ trusty-updates universe deb-src http://us.archive.ubuntu.com/ubuntu/ trusty-updates universe deb http://us.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse deb-src http://us.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse deb http://security.ubuntu.com/ubuntu trusty-security universe deb-src http://security.ubuntu.com/ubuntu trusty-security universe


Ubuntu 20.04 Keyboard navigation of Desktop Environment and Folders

I am unable to directly navigate the folders on my desktop environment using only the keyboard. Searching over internet, I couldn't find a shortcut to select a folder on the desktop (Example Recycle bin) and even after using the mouse to highlight/select on folder, I am unable to toggle between folders using the arrow keys or access the software pinned on the dock.


What is the rate of deterioration of lycopene in an open can of tomatoes?

Once I open canned tomatoes and transfer it to a glass jar, what is the rate of deterioration of their lycopene content?


Beamer: \nonumber equivalent for slides?

Is there an equivalent command to \nonumber when one doesn't want to include certain slides in the numbering? I would like to leave outline and title slides out of my numbering, and instead just number slides with actual content. Other workarounds would be nice to know about as well.  Edit: Since a MWE example was requested, here is one. Suppose I have a title page and two other slides. The code below gives a slide counter that goes up to 3, and the title slide is slide 1. I would prefer to have the title slide not be numbered, the counter go up to 2, and the the numbering start at the slide after the title. Here is some code.  \documentclass{beamer}  \mode<presentation>  {    \usetheme{Dresden}  }   \setbeamertemplate  {footline}{\quad\hfill\insertframenumber/\inserttotalframenumber\strut\quad}    \begin{document}  \begin{frame}  \titlepage \end{frame}  \begin{frame} Some actual content here \end{frame}  \begin{frame} Some more actual content here \end{frame}  \end{document}


Looking for proof of formula in WolframMathWorld article

I came across the formula (24) in the WolframMathWorld article on Web page  where no source of the proof could be identified by me.   The formula is $$\prod_{k=1}^{\lfloor \frac n2\rfloor}\sin(\frac{k\pi}{n})=\sqrt{\frac{n}{2^{n-1}}}$$  I am near a proof but it is rather intricate and maybe awkward and much to complicated.  Does anybody know the source of the original proof or is there an elementary homework-style one without deeper necessary experience ?


File ended while scanning use of \next, while using \begin{comment} on macro definition

On the question  I learned to do:  \documentclass[10pt,a5paper,twoside]{memoir}  \usepackage[T1]{fontenc} \usepackage[utf8]{inputenc}  \usepackage[brazil]{babel} \usepackage[showframe,pass]{geometry}  \newif\ifdebug \debugtrue % \debugfalse  \ifdebug \makeatletter  \@ifundefined{includegraphics} {     \newcommand{\includegraphics}[2][]{ includegraphics \detokenize{#1} \detokenize{#2} } }{}  \makeatother \else\fi  \begin{document}  \sloppy \includegraphics[width=\linewidth]{pictures/ex01}  \end{document}   Which generate the following PDF file:    So now would like to comment out the contents of the command, however when I added \begin{comment} & \end{comment} on \newcommand{\includegraphics}:  \@ifundefined{includegraphics} {     \newcommand{\includegraphics}[2][]{ \begin{comment} includegraphics \detokenize{#1} \detokenize{#2} \end{comment} } }{}   I got the error:  Runaway argument? ! File ended while scanning use of \next. <inserted text>                  \par  <*> ./test2.tex  I suspect you have forgotten a `}', causing me to read past where you wanted me to stop. I'll try to recover; but if the error is serious, you'd better type `E' or `X' now and fix your file.  ! Emergency stop. <*> ./test2.tex  *** (job aborted, no legal \end found)   How can the contents of the command be throw away?    Related:


Download Google web fonts, how to install it?

I used Terminal to download Google web fonts using commands listed below  apt-get install -y mercurial;     hg clone https://googlefontdirectory.googlecode.com/hg/googlefontdirectory;   I now have a directory in my home folder called " Google Font Directory ". It has sub folder named " ofl " which all font in separate folder. It seems there are 680 items. So dragging and dropping them to .fonts folder is almost impossible. Is there any method to install them automatically ? I have " Type Catcher " (just for your info). Please help me with this. Thanks.   PS : I use Ubuntu 12.04 LTS.


Non-locality of pre-Klein-Gordon equation

In Relativistic Quantum Mechanics, Bjorken and Drell state that expanding the square root in the equation $$-\hbar^2\frac{\partial^2\psi}{\partial t^2}=\sqrt{-\hbar^2c^2\boldsymbol{\nabla}^2+m^2c^4}\psi$$ would result in a non-local wave equation. What exactly do they mean by this? One could argue that in order to compute $\psi$'s spatial derivatives at a certain point in space-time up to arbitrary order, one has to know the behavior of $\psi$ in points arbitrarily far from the point of interest, even if there is no world line linking those points. But if we were to solve a local equation such as the Dirac equation, we could do that nonetheless. Accordingly, I think there must be a deeper reason for the non-locality that Bjorken and Drell warn for.


I'm just very new trying another operating system but me being into the music world needs a DAW, particularly Ableton...  I see it is possible to download but how should I proceed?


Is there a way to geomtrically visualize the identity (1³ + 2³ + ... + n³) = (1 + 2 + ... + n)², n ∈ ℕ? Are there any other similar identities?


Can not edit terminal text, it has always the same color

I accidentally deleted some files from home directory(after that my terminal was not like before) and now i can not edit it. I am choosing Edit->Preferences->Colors and there i am choosing different colors from palete but the terminal text is always the same in my case white. thanks in advance


Finding **cheapest** fares from a country to country/city/airport (including non-guaranteed connections)?

I've recently spent some time finding the cheapest fares for my journey and that got me thinking.  Essentially I'm traveling UK <-> Tallinn (Estonia) anytime within the next 4 months for a week. But I'm not bothered travelling through other airports or countries if that makes my journey cheaper (and as a EU citizen with no checked in luggage all the transfers shouldn't be a big hassle).  So currently if I search for MAN <-> TLL in flights.google.com that gives me the cheapest return for the end of May for about £190 with transfers (that's only because I've already bought my tickets so using end of May as an example to compare prices).  I live near Manchester but if I buy my tickets in advance (which I usually try to do) it doesn't matter if I fly from Manchester Airport, Edinburgh Airport, any airport in London or possibly anywhere from in the UK. Although it's less hassle to get back home from Manchester Airport - any airport in the UK presumably is fine for me as long as it's cheap (just an example to prove what I mean: I've spent £16.50 for the train ticket to get from Lancashire to Stansted Airport (London) and £14.05 to get from Manchester Airport back home, so there really is no big difference in price).  And if I choose London (all airports) <-> TLL that gives me around £100 for a direct return.  So currently I have purchased the following tickets: STN->TLL (£36.71), TLL->DUB (~£23.84), DUB->MAN (~£7.94). So that's about £69 in total for a "return". And I could have reduced that price even more (by buying STN->RYG (£13) & RYG->TLL (£12) instead of a direct one but I got a direct one because that one was better for me for that specific day only), or also had an option to fly MAN->DUB, DUB->TLL that would be again cheaper than my direct flight STN->TLL.  So the question is: I can of course find these routes and prices manually but it will take me days to look up every possible route between the UK and Tallinn (Estonia) and compare all the possible prices to narrow it down to 1-5 cheap options to choose from. I've used flights.google.com and skyscanner.net (and possibly some other ones) but none of them are able to find these cheap rotes that I can find manually (which is disappointing). Is there any website-software-anything that can find the cheapest tickets with layovers/transfers through other airports/countries from a country that I choose (for example the UK) to a country/city/airport (for example Estonia or Tallinn or TLL)?  P.S. Sorry for the long question but I had to provide my example to make it clear that the usual websites doesn't seem to find what I want to find.  EDIT1: Although broad searching is one aspect of my question, the most important one is actually finding the cheap connections automatically. Google or Skyscanner didn't see the possibility of flying cheaper like MAN->DUB->TLL or STN->RYG->TLL,  the only cheap option it knows about is the direct flight STN->TLL with Ryanair, although somehow the more expensive flights that it finds are with connections, so it can find flights with connections just not the cheap ones!  EDIT2: I've accepted Tor-Einar Jarnbjo's answer that explains why I couldn't find these cheap flights but if anyone knows a website that can still find these cheap flights please let me know! I accept all the risks!  EDIT3: As it was found out this question is a duplicate of  , although that original question was only answered because I've asked mine. :)


Separation theorem on the space of all complex continuous functions

Let $C$ be the Banach space of all complex continuous functions on $[0,1]$ endowed with the supremum norm. Let $B$ be the closed unit ball of $C$. Does there exist a $\Lambda\in C^*$ for which $\Lambda (B)$ is open? Note that $C$ is a locally convex space and $B$ is convex, balanced and closed set, by the separation theorem of convex sets,we know there exists $\Lambda\in C^*$ such that $|\Lambda f|\leq 1$ for all $f\in B$ and $|\Lambda f|>1$ for $f\in B^c$. But how about this when we consider some concrete space above?


In QGIS 2.14, in print composer I can save my project as a PDF file. There is no controls of the color space in which colors are specified in the output file. It will be very useful to have a choice of the color space: RGB or CMYK.  Is it possible to resolve this issue ?


Insert a PDF image (created in TeX) in a beamer slide

I am facing difficulty in sizing the PDF image being imported into the beamer slide presentation. This is because the original image generated in TeX has a lot of unused space. Please advise me how I should include the image. Using the document class standalone I get a compile time error. Perhaps a missing item.


Getting "Permission denied" even when using sudo command

I'm attempting to add a file to my /etc/apt/sources.list.d folder and for some reason despite using sudo it still says permission denied. Here's the code I'm trying to run.  $ sudo cat >> /etc/apt/sources.list   I've also tried simply using gedit but that doesn't work either.


Unwanted spaces in user defined structures and the uses of %

This question arise from my recent activity on user defined commands of various kind. In , @egreg pointed out to me the importance of not forgetting a % after the \end{minipage} environment delimiter (see also ), and I also noticed that a forgotten space ir <CR><LF> had enormous (1ex!) impact on the correct placement of two adjacent \parbox-es, defined on two consecutive lines of code for reasons of convenience. Therefore my question is: apart from the observation made by Kopka and Daly ([1], §10.5.2 pp. 199-200), do there exist general recommendations/practices to follow (or perhaps to comply with) when writing user-defined commands, codes, etc. in order to avoid causing "strange" formatting problems?  [1] Kopka, Helmut, Daly, Patrick W. (2004), "Guide to LaTEX", 4th ed., Boston etc.: Addison-Wesley, pp. xii+597.


has been recently bumped to the homepage by Community user. Bumping used to vote for answers, but in the current locked question voting is not possible. Why the question has been bumped?


I have this code:  String result = text;      String regex = "((\\(|\\[)(.+)(\\)|\\])){1}?";     Pattern pattern = Pattern.compile(regex);     Matcher matcher = pattern.matcher(result);      System.out.println("start");     System.out.println(result);     while (matcher.find()) {         System.out.print("Start index: " + matcher.start());         System.out.print(" End index: " + matcher.end() + " ");         System.out.println(matcher.group());     }     System.out.println("finish");   And I have a string that I want to match:  Some text sentence or sentences [something 234] (some things)   And the output I get when executing:  start some text sentence or sentences [something 234] (some things) Start index: 32 End index: 61 [something 234] (some things) finish   Now I actually want it to find the found cases in brackets separately, so to find: [something 234] in one match (some things) as the second match  Can anyone please help me build the regex accordingly? I am not sure how to put the reluctant quantifier for the whole regular expression, so I surrounded the whole bracketed elements in another brackets. But I don't understand why this reluctant quantifier is acting greedy here and what do I need to do to change that?


How can I add color to console input/output?

I want the prompt strings to be one color, and the user input to show in another color. Date=input ("Date: ") Market=input ("Market: ") Price=input ("Price: ")


latest version of QGIS fails to edit attribute table of GeoJSON file

I am using QGIS 3.6.4 and working with GeoJSON files. I have come across a very annoying problem. Whenever I try to add an attribute and assign values to it using the field calculator, the values will appear to update and the field looks correctly populated. However as soon as I exit out of the attribute table (while saving changes) and reopen it the entire column is converted to NULL.  I have tried playing around with the precision and width of the output field to no avail. I don't think this is related to coordinate system units since this is not a geometric operation of type $area or $length. It is more like Acol1+Bcol2.  Has anyone had such an issue before? Please help... I would have thought basic functionality like this is already well tested and bug free in QGIS....  EDIT  Other symptoms include:   new field disappears if I remove the layer and add it again from file location, despite having saved layer changes.... a separate geojson file called result.geojson.tmp is created and contains the modified attribute table. However my result.geojson is unchanged. Adding an attribute field and populating it should not create a new file but modify the current one in place... why does this happen? I have also attempted this with QGIS 3.6.1 - Same problem.   The problem appears to be under discussion in the


Eigenvalues of a sum of power of a matrix

$A$ is defined as a real $n×n$ matrix. $B$ is defined as: $$B=A+A^2+A^3+A^4+ \dots +A^n$$ What's the relation between eigenvalues of $A$ and eigenvalues of $B$? Can anyone give me some materials?


C# Regex does not match strings with a dot in

I am trying to do a find replace in a string of text. I am using Regex like this:  Regex regexText = new Regex("Test.Value");  strText = regexText.Replace(strText, value);   In this example I am trying to find the string "Test.Value" in a text string. However if this value appears in the string the replace does not happen.  If I remove the dots eg:  Regex regexText = new Regex("TEST");  strText = regexText.Replace(strText, value);   If I put the word "TEST" in the string, it replaces it just fine.  Is there a way to get this to work with strings with "."'s in?


How can I analyze performance issues before/during the logon process?

How can I analyze a performance issue that happens before or during the logon process?


free -m currently puts out something like this.     I would like to know using grep/awk how we can get the total free amount. i.e. 9083


Which of these is the fastest way to check if a list is empty in Python?

Before getting to the main question, I should first ask: When you're trying to check if a list is empty in Python, is there any case where the four cases below would yield a different boolean?   if not [] if not len([]) if len([]) == 0 if len([]) is 0   If not, which is the fastest way to check for this boolean and why? - i.e. what exactly is happening under the hood for each case? The difference may be trivial but I'm curious as to how these might differ during execution.


Does the uncertainty principle say that conservation of momentum is violated in quantum mechanics?

The uncertainty principle of Heisenberg says that the uncertainty in the position of a particle multiplied by the uncertainty of the momentum of a particle is always more than or equal to $\frac{\hbar}{2}$: $$\Delta x \Delta p \ge \frac{\hbar}{2}$$ Rearranging, you get this: $$\Delta p \ge \frac{\hbar}{2\Delta x},$$ which means that the uncertainty in momentum will never be $0$ unless the uncertainty in position is $\infty$. But that can never happen... I mean at maximum the uncertainty in position can't be more than a certain value because the universe doesn't have infinite space, right? Besides, if you think about electrons around an atom, that’s finite space. That would mean that there will always be an uncertainty in momentum... Meaning that momentum is not conserved... This question has been bothering me lately. It would be great if someone could give me an explanation.


I'm trying to start using plain tex (in fact, the pdftex that comes with texlive2010) to write a document but I'm having some trouble with the page layout. My question is at which point is it decided what the dimensions of the page and the margins will be?   As far as I investigated the \plainoutput routine in plain.tex only sets the height and width of the \box255 plus headers, footers, etc, but page dimensions (like A4, letter, portrait, landscape, etc) and margins are never defined. Moreover the TEXBOOK says that by default the page layout has 1in of margin at each side (page 251) but I don't know when are these margins defined nor why in my final pdf output the document appears with A4 size, 1in of left margin and approximatley 0.7in of right margin. So the question again is when are these dimensions decided?


Is there a place that lists SE site privileges for a user?

Is there a place on Stack Exchange that lists specific user privileges earned, such as question, answer, flag, vote, comment?  There's already a place to see user-earned badges.


Vigenere ciphertext encrypted with another vigenere cipher

I have been learning about Vigenere ciphers and then thought of this scenario: if a cryptographer encrypts a plaintext English message with a Vigenere cipher and then another cryptographer, who wants to ensure that the message is very secure, encrypts the ciphertext with another Vigenere cipher (with a different key length). Given only the ciphertext, how can you decrypt the message? A step by step explanation would be greatly appreciated.


How to get the concrete class name as a string?

I want to avoid calling a lot of isinstance() functions, so I'm looking for a way to get the concrete class name for an instance variable as a string.  Any ideas?


Coefficient of x^50 in the cube of a summation

What is the coefficient of $x^{50}$ in $(\sum_{n=1}^{\inf} x^n)^3$ ?  Does there exist a combinatorial approach to this problem?


Complexities of Recurrences in the form $t(n) = t(\alpha n) + t(\beta n) + cn$

When considering recurrence relations, they are generally of a form similar to  $$t(n) = t(\alpha n) + t(\beta n) + cn$$  and there are three cases to be considered for our values of $\alpha$ and $\beta$, being   $$\alpha + \beta < 1$$ $$\alpha + \beta = 1$$ $$\alpha + \beta > 1$$  We are able to show that for our first case, we receive $t(n) = O(n)$, and in our second case $t(n) = O(nlog n)$, but are we able to analyze the big-Oh for the third case? I know we can consider the third case to be $t(n) = \Omega(nlogn)$ but is it possible to draw any further conclusion?


Openlayers v4.0.1 support Google Maps Javascript API?

I want to know if the latest version of Openlayers (v4.0.1) supports Google Maps as a Tile Layer. I can't find any document ion about this. If Openlayers doesn't support Google Maps, could someone  tell me if there is any way to do this?


Determinant of $n\times n$ matrix $|i-j|$

For integer $n$ greater than or equal to 2, let $A_n$ be $n^{th}$ order square matrix whose $(i,j)$ component is $|i-j|$. That is, \begin{align*}     A_n =\begin{pmatrix}      0& 1& 2& ... & n-1\\     1& 0& 1& ... & n-2\\     2& 1& 0& ... & n-3\\     .& .& .& ... & . \\     .& .& .& ... & . \\     .& .& .& ... & . \\     n-1& n-2& n-3& ... &0     \end{pmatrix} \end{align*} Find the determinant of $A_n$. We have two general tools for the determinant of $n\times n$ matrix, they are co-factor formula and the Leibniz formula but I tried to build an expression for the determinant of this matrix but failed, Any hints would be appreciated. Leibniz Formular : $\det A = \sum_{\sigma \in S_n}\bigg(\text{sgn}(\sigma) \prod_{i=1}^n a_{i,\sigma_i}\bigg) $ I can figure this out for $3\times 3$ matrices but it is hard to think for $n\times n$ matrices with these permutations $\sigma$. And how do we find these kind of problems on the internet? Any recommendations would be appreciated


Displaying "traditional chinese" language text on web page

I have a web page that should display the characters on web page in Chinese language, however currently it is not displaying so:  Till now, I have implemented below written code, but still not able to fix:  in my header file:  <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />   mySql table is being set to:  CHARACTER SET utf8 COLLATE utf8_general_ci   The table shows Chinese characters without any fail. What else needs to be done to show the text on the web page?


Sum of infinite series when the ration isn't a constant

I'm looking for tips on how to solve this infinite series problem.  $\sum_{x=0}^{\infty}\frac{x}{4^x}$  I am pretty sure this series converges, but I don't know which method I should use to tackle this problem. At first I thought it was geometric, but the ratio isn't a constant: $r = \frac{a_{n+1}}{a_{n}} = \frac{x+1}{4x}$.  When this happens, how should I proceed?


Evaluation of $\int^{\infty}_{0} \frac1{1+x^n}dx$ with the use of Residue theorem

Could anyone advise me on how to show$\begin{align} \int^{\infty}_{0}\end{align} \dfrac{1}{1+x^n}dx=\dfrac{\pi}{n\text{sin}\dfrac{\pi}{2}} ,\ $ for all integers $n \geq 2 \ ?$ Thank you.  Here is my attempt:  Let $f:\mathbb{C} \to \mathbb{C}$ be defined by $f(z)=\dfrac{1}{1+z^n}.$  $z_k=e^{\dfrac{(2k+1)\pi i}{n}}, k=0,...,n-1,$ are all the roots of $z^n+1$ and they are simple poles of $f.$   For $R>1,$ let $\gamma_R(t)=Re^{it}, t\in[0,\frac{\pi}{2}].$ Then,$\ \gamma_{R} +[0,R]$ is a positively oriented closed contour whose interior contains $z_k,$ where $k \leq \dfrac{\frac{n}{2}-1}{2}=w.$    $\text{Res}_{z=z_k}f(z)=\text{lim}_{\ z \to z_k}(z-z_k)f(z)=\dfrac{1}{nz_k^{n-1}}.$  By Cauchy Residue theorem, $\begin{align}2\pi i\sum_{k \leq w}\text{Res}_{z=z_k}f(z)=\int^{R}_{0} \dfrac{1}{x^n+1}dx+ \int_{\gamma_{R}}f(z)dz\end{align}.$  But how do I evaluate $\begin{align}\sum_{k \leq w}\text{Res}_{z=z_k}f(z) \ ? \end{align} $


So a few years ago I came up with the idea of a magneticly powered wheel that could be attached to a generator and power it, it would not be infinite as over time magnets lose their power yet I think it could work. It uses some bar magnets, some 3d printed parts, an axle, a bearing (if its not attached to a generator) and some magnetic shielding material (like the stuff on this link: )  The way it works is its effectively a circle with a bunch of bar magnets attached to it with their northern poles pointing towards the circle's centre and their southern poles pointing away from the centre of the circle, some magnetic shielding material is then used to cover the left side of the northern poles of these magnets. Then the bearing is placed in the centre of the circle and some more bar magnets attached to the axle, more magnetic shielding material is used to cover these bar magnets apart from their very ends, the axle is then inserted into the bearing. At this point I am unsure if it will do any of these three things:   The axle spins into life, accelerating so quickly that the whole mechanism shatters and pieces go flying everywhere. The wheel does not immediately start spinning but when I give it a nudge it once again spins into life and shatters. Nothing happens   I am wondering what you all think about the possibility of this and potential problems it may have (apart from things like air resistance).


In a memory of Dumbledore's, Tom Riddle asks Slughorn about Horcruxes. He says that he wants to split his soul into seven pieces. But Harry is the seventh and unintended one. So aren't there 8 Horcruxes in total, considering that Voldemort already split his soul into 7 pieces? Or have I made a mistake while counting?


What's the difference between "Layers" and "Tiers"?


I have a quest from the 'Companions' to kill an escaped prisoner. He is said to be roaming Haarfingar.   When I bring up the journal and highlight the quest, It offers no clues on the map.  I have been to Solitude and search a few keeps etc. Also tried the 'Clairvoyance' abilty.  In all honesty he/she could be anywhere in a large area !!  Anyone have any advice please ?


What's the purpose of memory alignment and why I do need it?

I've been reading so much about memory alignment and I didn't get it, I know that's an important method that you have to keep in mind to write efficient code. But I got confused.


the default new form in my sharepoint online calendar got deleted and it won't let me create a new one I have tried creating it from sharepoint designer but it throws an error, i have deleted designer cache but it did not help


SQL Server 2012: Generate Scripts from command line

I am running SQL Server 2012.  The SQL Server Management Studio has the option to right click on a database then select Tasks and Generate Scripts.  Is there a way to automate that via command line somehow?  I want to create a script that includes the schema and data of the entire data base.  Tools like ScriptDB and sqlpubwiz.exe all seem to target SQL Server 2005. What about SQL Server 2012?


My friend said he knows this guy who will deposit money into my Chase bank account. The only requirements being that I have had the account for over 4 months and my balance is not negative.  His name is Antonio and he states he can set me up with a payroll; deposit $1,500 into my account once a month for the next 3 months. When I asked where this money is coming from he stated from Ghost Accounts.  What is this?! It sounds illegal/fraud. Anyone heard of something like this?


Gparted cannot enlarge my Ubuntu partition although I have some unallocated space on the drive

I'm trying to enlarge the home partition on Ubuntu. When I click on resize in GParted, it can't be done even though I have 100 GB of unallocated space:


So I've been trying to get big factorials like 50 using BigInteger. But when i run this program in cmd, i get unexpected error at line 16: fact=fact.multiply(new BigInteger(getFactorial(n-1))). I am not even able to see the thrown exception as it gets scrolled out. Please help me find the error.  import java.math.BigInteger; class FactorialUsingRecursion {  public static void main(String args[]) {     int num=50;     String fact=getFactorial(num);     System.out.println(num+"! = "+fact); }  static String getFactorial(int n) {     BigInteger fact=new BigInteger(n+"");      if(fact.toString()=="1") {         return "1";     }     fact=fact.multiply(new BigInteger(getFactorial(n-1)));//error line     return fact.toString(); } }


I want to be able to use   IndexOrderDefault Descending Date   for all of my sub-folders, but I want to the first page to be sorted by name (A-Z)  I read  but I do not seem to be able to use <Directory> in .htaccess  My next thought was that perhaps I could use mod_rewrite to  redirect people from    to    But so far I have not been able to figure out how to do this.  (In case it isn't blatantly obvious, I am a complete newbie at this and may be missing something obvious.)


NullPointerException in my code. May I ask how to fix it?

import java.awt.*; import java.awt.event.*; import javax.swing.*; public class Test implements ActionListener{     static JFrame frm = new JFrame("Calculator");     static JPanel jp1 = new JPanel(new FlowLayout());     static JPanel jp2 = new JPanel(new GridLayout(3, 3));     static JButton []btn = new JButton[9];     static JTextField txtOut = new JTextField(15);      static Container cp = frm.getContentPane();      public static void main(String args[]){         cp.setLayout(new BorderLayout(0, 10));          jp1.add(txtOut);         cp.add(jp1, BorderLayout.NORTH);          for (int i = 0; i < 9; ++i){             btn[i].setText("" + (i + 1));             btn[i].addActionListener((ActionListener)frm);             jp2.add(btn[i]);         }         cp.add(jp2, BorderLayout.CENTER);          frm.setSize(200, 200);         frm.setVisible(true);          frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);     }     public void actionPerformed(ActionEvent e){         JButton tmp_btn = (JButton) e.getSource();         // check which button         for (int i = 0; i < 9; ++i){             if (tmp_btn == btn[i]){                 txtOut.setText("" + (i + 1));                 break;             }         }     } }   Hello, I am studying in Java Swing course.  I tried to make a calculator,   but when I handle Event Listener, I face a problem!  It's java.lang.NullPointerException.  I guess the problem is in main method's for loop's three statements,  because I tried to comment them respectively,   and the IDE compiler talk me "NullPointerException" is in there...  But I still don't know what's wrong in this code.  So, I want to ask, ho to fix it, thanks!!  (Sorry I'm poor at English :(...


Dropped the Wedge of a quill stem in the head tube

Trying to remove a seized quill stem and did a beginner's mistake of removing the stem bolt. I could not thread back the bolt.    Is there a better way to thread back the bolt to the wedge for me to start all over again the process of removing the quill stem?  Thanks


ZSH wont install on fresh ubuntu 20.04 (rpi4)

I've just installed 20.04 on my new rpi4 8gb and I'm trying to install ZSH. It should be in the main repo and should be installed with sudo apt install zsh. Unfortunently it throws an error: E: Unable to locate package zsh. I haven't changed anything in my sources.list. my sources.list: ## modifications made here will not survive a re-bundle. ## if you wish to make changes you can: ## a.) add 'apt_preserve_sources_list: true' to /etc/cloud/cloud.cfg ##     or do the same in user-data ## b.) add sources in /etc/apt/sources.list.d ## c.) make changes to template file /etc/cloud/templates/sources.list.tmpl  # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to # newer versions of the distribution. deb http://ports.ubuntu.com/ubuntu-ports focal main restricted # deb-src http://ports.ubuntu.com/ubuntu-ports focal main restricted  ## Major bug fix updates produced after the final release of the ## distribution. deb http://ports.ubuntu.com/ubuntu-ports focal-updates main restricted # deb-src http://ports.ubuntu.com/ubuntu-ports focal-updates main restricted  ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team. Also, please note that software in universe WILL NOT receive any ## review or updates from the Ubuntu security team. deb http://ports.ubuntu.com/ubuntu-ports focal universe # deb-src http://ports.ubuntu.com/ubuntu-ports focal universe deb http://ports.ubuntu.com/ubuntu-ports focal-updates universe # deb-src http://ports.ubuntu.com/ubuntu-ports focal-updates universe  ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu ## team, and may not be under a free licence. Please satisfy yourself as to ## your rights to use the software. Also, please note that software in ## multiverse WILL NOT receive any review or updates from the Ubuntu ## security team. deb http://ports.ubuntu.com/ubuntu-ports focal multiverse # deb-src http://ports.ubuntu.com/ubuntu-ports focal multiverse deb http://ports.ubuntu.com/ubuntu-ports focal-updates multiverse # deb-src http://ports.ubuntu.com/ubuntu-ports focal-updates multiverse  ## N.B. software from this repository may not have been tested as ## extensively as that contained in the main release, although it includes ## newer versions of some applications which may provide useful features. ## Also, please note that software in backports WILL NOT receive any review ## or updates from the Ubuntu security team. deb http://ports.ubuntu.com/ubuntu-ports focal-backports main restricted universe multiverse # deb-src http://ports.ubuntu.com/ubuntu-ports focal-backports main restricted universe multiverse  ## Uncomment the following two lines to add software from Canonical's ## 'partner' repository. ## This software is not part of Ubuntu, but is offered by Canonical and the ## respective vendors as a service to Ubuntu users. # deb http://archive.canonical.com/ubuntu focal partner # deb-src http://archive.canonical.com/ubuntu focal partner  deb http://ports.ubuntu.com/ubuntu-ports focal-security main restricted # deb-src http://ports.ubuntu.com/ubuntu-ports focal-security main restricted deb http://ports.ubuntu.com/ubuntu-ports focal-security universe # deb-src http://ports.ubuntu.com/ubuntu-ports focal-security universe deb http://ports.ubuntu.com/ubuntu-ports focal-security multiverse # deb-src http://ports.ubuntu.com/ubuntu-ports focal-security multiverse


I've done very little print work before and now that I'm in need of some product labels, I've come across 5-10 color printing. The local shops haven't been very helpful. How is it different from regular CMYK? Or is it a different process entirely?


safe to assign uint32_t variable to a signed value

I recently came across a code where                   uint32_t index = -1;   Is this safe to use the above.Assume that the code will have to be compiled across multiple Linux platforms and distributions.Or is it recommended to use a signed value? if I compare it against -1 somewhere in the program is it likely to compare -1 with 0xffffffff and throw an error or manifest some other strange behaviour.


There are a few cards that allow you to exile cards and then cast them later ( for example). After a spell cast this way resolves, does it go back into exile, or does it resolve normally including being placed in its owner's graveyard? (assuming nothing else effects where it would go after being cast)


What's the best stack up for a four layer board with two power planes (plus and minus a dc voltage), a ground plane, and a signal plane? Can anyone share a resource that talks about the best practices for stack up and why they are the best practices? I can't find many things that address having two power planes. Is the following an acceptable stack up, or should the signal and ground planes be adjacent?  Signal +VDC -VDC Ground


Long URL in Bibliography section exceeds the bounds of the page

I have an external bib where I put a reference to an external URL.  @misc{myreference,   author = {The Author},   title = {The Title},   howpublished = "\url{http://thisismyurl/2010/3/a-long-url-here}",   year = {year} }   When I compile, the URL (when displayed in Bibliography) exceeds the bounds of the page (set as customs). The URL is composed by different terms concatenated with - symbol. a-long-url-here can be the following:  abc-abc-abca-abc-ab-abc-abc-abc-a-abcabc-ab-abc-abc/   The bib is inserted in the following manner:  \bibliographystyle{IEEEbib} \bibliography{bibliog}   Is there any mechanism to fix this behaviour? I checked  but I don't know how to use it in my situation.  Edit  For the sake of completeness, I use PdfLatex.


Does the order, lattice of subgroups, and lattice of factor groups, uniquely determine a group up to isomorphism?

If we have a two lattices (partially ordered) - one for subgroups, one for factor groups, and we know order of the group we want to have these subgroup and factor group lattices, is such a group unique up to isomorphism (if exists)? Or is there a counterexample?  If that's true, are sufficient conditions on the order and subgroup lattices to guarantee uniqueness? Another way - what if we now lattice for subgroup and group of automorphism of group; is that group uniquely determined by that information?  Thanks for help. (sorry for English)


For Installing gcc+ in Git for the Windows bash environment I can't seem to find anywhere the proper order of which should I download first? And how I would go about setting up the PATH environment.   I've only ever set up a python environment, and recently new to Windows, the past 10 years or so I've only ever had a macOS set up.  I was told I need the MinGW for windows, and I thought i already had that configured when I downloaded GIT, but the terminal doesn't recognize any of the commands for gcc+ or provide a version set up for it.  So I assume I have to download it separately. I wasn't sure if there is a specific order to use in setting up  the gcc+ environment for GIT command line if I should download MINGW for windows first and set it up, or GIT first.  And if so how i would go about providing the appropriate PATH to  be able to run and compile programs inside the GIT CLI Bash  Any help is greatly appreciated thank you.


What equipment is required for a home studio?

I'd like to convert a room downstairs into a home studio to do mostly portrait/fashion/pet photography. I have a few strobes, softboxes, and stands, but that's it. What are the bare basics needed to get started?


I have a 240fps video and I want to merge/average every 4 frames into 1, resulting in a 60fps video with a motion blur type effect. Any ideas how I can do this with ffmpeg?


Simulating data based on correlation coefficient?

If a numerical vector $\vec{x}$ is a sample drawn from a normal distribution, given a correlation coefficient $\rho$ is there a way to simulate a second vector $\vec{y}$ such that the $corr(\vec{x},\vec{y})=\rho$ ?  My hunch is that $\vec{x}$ would be multiplied by a sample of equal length from a random uniform distribution centered around 1 and bound by some interval determined by the value of $\rho$, but I'm just guessing.


I have ubuntu 11.04 installed in my PC. Now, the system does not allow me to update or upgrade anything. So, I would like to use one of your LTS version. I prefer 14.04, as it is new. I am having a dual booting PC with ubuntu 11.04 and windows-7. I want to remove ubuntu 11.04 and in its place I would like to install 14.04. So, kindly suggest me how can I proceed with installation.


First of all: No I didn't get the phone off of someone else and no I can't get the password by going to iforgot.apple.com (because the email address used for the account has been deleted, so emailing doesn't work)  The iPhone is currently in the state where it acts like you just got it (because I tried to reset the phone by typing the wrong passcode 10 times), but after going through a few steps it will ask for the iCloud username and password. I don't care about any of the data on it, I just need to delete everything off it, so I can actually do something with it.


I have this simple snippet: <!DOCTYPE html> <html>     <head>         <link rel="stylesheet" type="text/css" href="css.css">     </head>     <body id="background-image"     style="background-image: url('background.jpg');" >         <div class="container">             wii jlkjkljkl fjkl jlkfsjlkfj klsajfkl sajkl jfklasj kfjsakl jlkfajs klfjlkasj fklasj klfjsakl lkfas         </div>     </body> </html>  and the content of css.css is: #background-image {     background-repeat: no-repeat;     background-attachment: fixed;     background-size: cover;     background-position: center center; }  .container {   display: flex;   align-items: center;   justify-content: center; }  I can't display the text in the center of the screen. It's centered horizontally, but not vertically. That is, I see a background image with the text centered horizontally at the top of the image. And I want to have the text right in the center. What's wrong? I thought the combination of flex and align-items:center was enough to make this happen.


I have a production server running with the following flag: -XX:+HeapDumpOnOutOfMemoryError  Last night it generated a java-38942.hprof file when our server encountered a heap error. It turns out that the developers of the system knew of the flag but no way to get any useful information from it.  Any ideas?


In the Metropolis algorithm, if the ratio of probabilities $r$ is less than $1$, why not directly reject instead of accepting with probability $r$?

Suppose that we want to sample from a posterior distribution $p(\theta|y)$ but we do not know how to directly sample. Suppose instead that we have a working set of values $\{\theta^{(1)}, \ldots, \theta^{(S)}\}$ and that we have a new draw $\theta^{*}$ that we want to know if we want to set equal to $\theta^{(S+1)}$, the next value of the set.   Then, the algorithm states to look at:  $$ r = \frac{p(\theta^{*}|y)}{p(\theta^{S}|y)} $$  If $r>1$, then $\theta^{*}$ is in a sense more likely than $\theta^{(S)}$, so we set $\theta^{*} = \theta^{(S+1)}$.   Now, if $r<1$, then $\theta^{*}$ is in a sense less likely than $\theta^{(S)}$. Then, we set $\theta^{*} = \theta^{(S+1)}$ with probability $r$ and $\theta^{*} = \theta^{(S)}$ with probability $1-r$.   This is where I am confused, if $p(\theta^{*}|y) < p(\theta^{S}|y)$, shouldn't we just directly reject $\theta^{*}$ since it is less likely to occur? Why do we even have this scheme where we will accept it with probability $r$? Why not directly remove it? Thanks.


Can I automatically log in to open WiFi that requires web login/password?

There are lots of wifi hotspots that are open, but require a web-based login to use. Hotels, coffeeshops, workplaces. For password-protected wifi, it's easy to set up Android phones to remember the login and password. But I'd like to be able to use my workplace's open wifi with web-based password on a regular basis, without having to manually type stuff in. It should just automatically connect to the Wifi router, go to  or whatever, type in my password, and then everything else should just work. Is this possible?  (HTC Evo running Android 2.2, fwiw...)


Drift velocity (explained to me as how fast the electrons are moving) is really slow. My book says the electrons move at around 10 mm/ s.  If electrons move so slowly how do circuits work so fast? If you make a basic circuit with just a light bulb, the bulb lights up almost immediately after you connect the wire to the positive terminal.


Does the time has a direction or dS>0 makes this illusion?

If there is space-time, and you can move in space in each direction, like forward and backward, why does time seem to have a direction? Can’t simply be possible to move in each direction also in time? What gives the illusion of time direction, can not it be explained by dS>0? Also moving backward in the time causes entropy to grow. So we think that we can not move back.


I have a file  content like below  cat file  Hello How are you ? I am good Watsapppp bla bla    But When I am exporting and echoing its value/content , This gives everything in same line and bit different.  export filename=$(cat file)  echo $filename Hello How are you 0 1 2 3 a m p q I am good Watsapppp bla bla   My Requirement in script is to print same content as in file.  Should be  $filename Hello How are you ? I am good Watsapppp bla bla   I mean when I pass the value of $filename , it should print above content


I've been doing a lot of research about functional half-iteration, and I posed the following question to myself:     Consider the function $q:\mathbb R\mapsto\mathbb R$ defined as   $$q(x)=x^2+1$$   Does $q^{\circ 1/2}$ exist? Does a continuous $q^{\circ 1/2}$ exist? What about a differentiable $q^{\circ 1/2}$?   It seems to me that $q^{\circ 1/2}$ exists, but I don't know how to prove that it exists (I certainly can't find it, since it's probably not an elementary function). So far, I've proven that if it exists and is continuous, then it must be bounded between $x$ and $q(x)$. My intuition tells me that a differentiable solution probably exists... but it may not be differentiable at $x=0$. I've worked out an "almost-graph" of a possible solution, but it's far from a rigorous proof:    Any ideas about how to attack this problem rigorously?


Integral mean value theorem- relate a point in the derivative to an integral

Question:  Let $f:[a,b] \to \Bbb R$ be a continuously differentiable function s.t $f(a)=f(b)=0$ Prove that exists a point $c \in (a,b)$ such that $$ |f'(c)| \ge \frac 4{(b-a)^2} \int ^b_a f(x) dx $$ What we did: We tried using the integral mean value theorem and then using LaGrange theorem, but ended with a sum of 2 points $(f'(y_1) + f'(y_2))$ in $[a,b]$ that we didn't know how to connect to $|f'(c)|$.  2nd try (using Newton Leibnitz, and then LaGrange theorem twice): $|\frac 4{(b-a)^2}\int_a^b f(x)dx| = |\frac 4{(b-a)^2}(F(a)-F(b))|=  |\frac 4{(b-a)} \frac{(F(a)-F(b))}{b-a}| = |\frac 4{(b-a)} f(c_1)|= |\frac 4{(b-a)} \frac {(f(c_1)-f(a)) (c_1-a)}{c_1-a}|= |\frac {4(c_1-a)}{(b-a)} \frac {(f(c_1)-f(a))}{c_1-a}|= |\frac {4(c_1-a)}{(b-a)} f'(c)|$  our problem with this try is that we don't know how we can bound the last expression with f'(c)


Destroying a user can leave a bounty open on a deleted question

is a bit of an odd case.  The user placed a bounty on it, then engaged in a rollback war culminating with a lock. He then requested his account to be deleted. It was. The question, which was at -1 at the time, was automatically deleted along with the account. This should not happen since bounty questions ordinarily can be neither closed nor deleted.  Now the bounty languishes in a limbo state, its clock ticking away in futility, hoping against desperate hope that someone somewhere will rescue it. But no one hears its cries.    Cheer? No, I'm afraid not.


Word usage of "not to fly" vs "to not fly "

I often read the phrase "not to" preceding an action, as in "not to run" or "not to swim". It seems awkward. Please explain explain the usage.


What is the command to make a command block emit a redstone signal after 20 mins

How can I make a command block emit a redstone signal after 20 mins. I want it to emit a  redstone signal after 20 mins to power another command block that will have /tp to send all players to a certain area. It will also need some thing that resets it to 20 mins


"which alias" and "whereis alias" doesn't return anything

I recently installed Ubuntu 20.04.  I am unable to find the alias command.  When I enter which alias I get nothing back.  Same with whereis alias.


What is the word for "something that needs prompt attention and resolved quickly"

We usually encounter some cases at workplace "something that needs prompt attention and resolved quickly" ,is there a professional word we can use for this casE?


If $f(z)$ analytic in the domain $D$ and $f'(z)=0$ so $f(z)=$constant?

I've been thinking how to prove that an analytic function $f$ in the domain $D$ is a constant if  $f'(z)=0$ in every point in $D$, but I haven't figured it out yet.  What I was thinking is to use Cauchy-Riemann equations, but it didn't work well...  If this is not true, I would like to know the counterexample...  Here is what I tried:  Let $f(z)=u(x,y)+iv(x,y)$  $\color{blue}{(1)}\text{(Cauchy-Riemann})\begin{cases} u_y=-v_x\\ u_x=v_y \end{cases}$  $\color{blue}{(2)}\lim\limits_{\Delta z \to 0}\frac{f(z_0+\Delta z)-f(z_0)}{\Delta z }=0$ for all $z_0$ in $D$  I'm stuck here...


How to check that a div exists jquery and if it does do nothing

I'm trying to check to see if an div called .errormsg exists and if it does then I don't want anything to happen but if it doesn't exist i want my form to redirect to a new URL after it. This is what I've done but I'm not sure it's correct at all, I'm only learning so any help would be much appreciated   thanks


What's wrong with my solution for the birthday problem?

So what I decided to do is to start a small case with only 3 people. There are three possible combinations that I could pair up the people, using the symbols A, B, and C to represent the persons involved: A&B, A&C, B&C. The probability of each pair having the same birthday is $1\over365$ (the first guy gets any birthday, and the second guy only gets one birthday to choose from). What my intuition directed me to do next is to find the probability that any of the three events are true, or the union of the three events, which involved adding up the probabilities.   To put this generally, the equation for the probability SHOULD be:  ${n \choose 2} \div 365$  However, clearly this is not the case since $n \choose 2$ gets over 365 when $n = 28$. And with 28 people, there is obviously still a chance that they all have different birthdays (Person 1 has Jan. 1, Person 2 has Jan. 2. ... Person 28 has Jan. 28). Could anyone tell me what's wrong with my intuition? I don't want to know what's the right solution, I just want to know what's wrong with my solution .. it makes sense to my intuition, even though it's incorrect.


I don't use the launchpad, especially as it has a lot of useless apps in there that you can't delete either. For things like the dock and the dashboard I found guides online on how to remove them, but none for launchpad. Is it possible to remove launchpad completely (on OS X 10.9.4)?


Design Patterns - Adapter pattern vs Decorator Pattern?

I have been reading about design patterns and this got me curious:  Decorator Pattern says wrap an original object and add additional features in the wrapper object. So structurally speaking - Wrappers follow decorator pattern.  Adapter pattern says changing one object by creating an instance of it and adding functionalities to it. These functionalities do not match those of the original object so we have to modify them, but we may also add our own extra methods which are not a part of the original object.  In this regard, what is the difference between Adapter and Decorator design pattern?


Is it grammatically correct to place the object of preposition before the preposition?

In conversation, it's normal to say:     What time do you have to be at the train station by?   Note: What time do you have to be at the train station vs What time do you have to be at the train station by, mean 2 completely different things, right?  1) The question in the title  2) Whether by is a preposition or not.  Winston Churchill once said     "That is the sort of thing up with which I will not put!


Consider the function $g(x) = \frac{e^x-1}{x}$. Find a general formula for $g^{(n)}(x)$ (i.e. the $n-th$ derivative of $g(x)$) and prove that this formula is correct.   I just want to ask can I use, finding the sum of a series by  differentiating or should I use they Taylor series


What is the Jacobian matrix?  What are its applications?   What is its physical and geometrical meaning?  Can someone please explain with examples?


"Weaker continuum hypothesis:" $2^{\aleph_0} < 2^{\aleph_1}$?

For finite cardinals $A < B$, it's clear that the powerset $2^A$ is smaller than the powerset $2^B$. However, it seems that when $A < B$ are infinite cardinals, the strict inequality cannot be proven from ZFC:  tells us that in general, unless something is known about the cofinalities $\text{cf}(A), \text{cf}(B)$, the most we can say is that $2^A \leq 2^B$. (That is, there are models for which both $2^A = 2^B$ and $2^A < 2^B$.) My question is about the smallest possible case: $A = \aleph_0$, $B = \aleph_1$. If we had that $\aleph_1 = 2^{\aleph_0}$ (Continuum Hypothesis) then obviously we would have $2^{\aleph_0} < 2^{(2^{\aleph_0})} = 2^{\aleph_1}$, but it seems like that's probably a lot stronger than we would need to show $2^{\aleph_0} < 2^{\aleph_1}$. Contrapositively, if $2^{\aleph_0} = 2^{\aleph_1}$, that would imply the negation of the Continuum Hypothesis, but again, this seems like a very strong sufficient condition for $\neg CH$ that wouldn't be necessary. Can we show for sure that $2^{\aleph_0} < 2^{\aleph_1}$ or $2^{\aleph_0} = 2^{\aleph_1}$? Is there simply no canonical way to answer this (any more than for the Continuum Hypothesis)? What is the status of this question, and are there any well-known open statements to which it is equivalent? I played around with it in a desultory way to discover why approaches like diagonalization or Konig's theorem wouldn't work to establish an injection $2^{\aleph_1} \to 2^{\aleph_0}$ or lack of same, but maybe there are some cleverer techniques out there I'm not familiar with.


In Avengers: Endgame, how was Nebula from past able to bring Thanos and the army into the future?   The Avengers who build the machine could not do this and required Pym particles which they were short of and had only limited attempts to travel time.


How long does it take to install Ubuntu 13.04

I am trying to install Ubuntu 13.04 after an upgrade t Ubuntu 13.10(13.10 not compatible with Zend Server/Apache 2.2)  It seems after the 'preparing to install screen the installation just sitting there, nothing happens" but busy indicator spinning... no error msg??


Disable working of browser's back button on logout in jsp

I am developing a web application using struts2 and jsp. I want to implement logout functionality in it. Although, I am able to remove the session but the browser's back button sends me back to the previously visited pages. I added the following code in each of the jsp file for preventing the caching. But this is not working. Kindly help.. So that after logout one cannot access the pages.     Code :-   <% response.setHeader("Cache-Control","no-cache"); // HTTP 1.1  response.setHeader("Pragma","no-cache"); //HTTP 1.0  response.setDateHeader ("Expires", 0);  %>  I have added this code in head tag of each and every jsp page.


How to host a single website on multiple servers?

I'm planning on releasing an iOS app that downloads video from my server. If hundreds of people on the launch day try to do this, then my website and the services that my server provides will clearly go down. How do you host a website on multiple servers? When someone tries to access my site, how is their request passed to an available server? How do Apple and Google do it? Thanks for your help.


Who are the Kingsguard with Cersei in S8E05?

Assuming  list of candidates is still accurate: who are the two Kingsguard / Queensguard accompanying Cersei and Ser Robert Strong through the Red Keep when they      encounter the Hound, and get run through in short order,    in S8E05?  Edit: This question is about an entirely different season and episode than the  reference, which names 6 of the 7 guards at that time, and so is not a duplicate.  I'm asking about who is left now; specifically, who are the 2 in this scene.  If it is known.


Why Great Britain or England/Scotland/Wales/Ireland in different sport?

Why is it that, in different sports, athletes represent different "countries"?  In football, curling, rugby (both union and league), and other sports, there are England, Scotland, Wales, and Ireland teams;  In other sports, such as tennis, swimming, and athletics, there's only a single Great Britain team instead.   In some sports there are different national teams, in other sports only a Great Britain team.


Well, probably this might seem a really simple question (and it might be so too!), but off late me and my friends have been debating quite hard over this question.     Is $3 \ge 1$ or is it just $3 > 1$?   Actually it all started here: if functions $f$ and $g$ satisfy $f>g$ then do they also satisfy $f \ge g$? All of us agreed. (are we wrong here itself?). After all, the $\ge$ symbol is basically 'greater than' OR 'equal too'. So if a function $f$ takes values greater than $g$, then definitely it satisfies the $\ge$ relation.  But then somehow the above mentioned question came up. My friends say that $3 \ge 1$ is absolutely wrong. Their reasoning: "under no circumstances can 3 be equal to 1", so $3 \ge 1$ is wrong.  My argument: $3 \ge 1$ is a mathematical statement which can either be true or false. It states that 3 is either greater than OR equal to 1. One of the conditions is satisfied and the two conditions are linked by an 'OR'. So $3\ge 1$ is true.  Who's right?  (please edit or add tags as i don't know what to tag the question as!)


How to get computer name and local ip address in LAN with React

I want to send them via http to api for logging pupposes. I have found several js solutions but all of them do not work, giving 'undefined' or (for ip) '127.0.0.1'. Is there any working solution for React?


After sudo apt-get install awesome awesome-extra and logging into it (with no previous configuration that I know of), there's no menu entry for Firefox. All my other stuff is there - Mutt, Meld, jEdit, BOINC, etc., only Firefox is missing. I have no ~/.config/awesome/ directory, so there should be no override in place.


Relation Between Partial Correlation and Beta Coefficient in Multiple Regression

Suppose I've a multiple regression coefficient in the following form:  y = β0 + β1x1 + β2x2 + β3x3 + β4x4 + ϵ   My question is how to calculate the relationship between partial correlation and beta coefficient in this case. The question is an extension of the following . In this question @ttnphns showed the equation from where we can calculate beta coefficients from partial correlations. But he showed it in 2-predictor situation. I want to know if it can be extended to n-predictor situation.


I am getting a null pointer exception when I try to add a new entry to an observable list

I apologize if my knowledge and Java standardization is poor. I'm new to the language and self-taught. I'm trying to put together an inventory program, and I'm using observable lists to store instances of a part class that has two subclasses. The observable lists are stored in an Inventory class. At any point in the program runtime, if there's an instance of a Part being added to the Parts List, a null pointer exception is thrown. The segments of code below are stored in separate files. public abstract class Part { private int partID; private String partName; private double partPrice; private int partStock; private int partMin; private int partMax;  public Part(){     this(0, null, 0, 0, 0, 0); }  public Part(final int partID, final String partName, final double partPrice, final int partStock, final int partMin, final int partMax){     this.partID = partID;     this.partName = partName;     this.partPrice = partPrice;     this.partStock = partStock;     this.partMin = partMin;     this.partMax = partMax; }  public void setPartID(final int partID) {     this.partID = partID; }  public int getPartID() {     return this.partID; }  public void setPartName(final String partName) {     this.partName = partName; }  public String getPartName() {     return this.partName; }  public void setPartPrice(final double partPrice) {     this.partPrice = partPrice; }  public double getPartPrice() {     return this.partPrice; }  public void setPartStock(final int partStock) {     this.partStock = partStock; }  public int getPartStock() {     return this.partStock; }  public void setPartMin(final int partMin) {     this.partMin = partMin; }  public int getPartMin() {     return this.partMin; }  public void setPartMax(final int partMax) {     this.partMax = partMax; }  public int getPartMax() {     return this.partMax; }  }  public class InHouse extends Part{  private int machineID;  public InHouse() {     this(0, null, 0, 0.0, 0, 0, 0); }  public InHouse(final int partID, final String partName, final int partStock, final double partPrice, final int partMin, final int partMax, final int machineID) {     super(partID, partName, partPrice, partStock, partMin, partMax);     this.machineID = machineID; }   public void setMachineID(final int machineID) {     this.machineID = machineID; }  public int getMachineID() {     return this.machineID; }   public class Outsourced extends Part{     private String companyName;  public Outsourced() {     this(0, null, 0, 0.0, 0, 0, null); }  public Outsourced(final int partID, final String partName, final int partStock, final double partPrice, final int partMax, final int partMin, final String companyName) {     super(partID, partName, partPrice, partStock, partMin, partMax);     this.companyName = companyName; }   public void setCompanyName(final String companyName) {     this.companyName = companyName; }  public String getCompanyName() {     return this.companyName; }   Pardon the "Inventory2." My NetBeans behaves as though "Inventory" is a file that already exists, even though there's nothing of the like in my project files. public class Inventory2 { public static ObservableList<Part> parts;  public Inventory2() {     parts = null;  }  public static void addPart(Part part) {     parts.add(part); }   This is a code snippet that generates a null pointer exception. Inventory2 inventory = new inventory2();     final InHouse partToAdd = new InHouse();             partToAdd.setMachineID(1234);             partToAdd.setPartName("generic");             partToAdd.setPartStock(2);             partToAdd.setPartPrice(10);             partToAdd.setPartMin(1);             partToAdd.setPartMax(15);             partToAdd.setPartID(1);     inventory.addPart(partToAdd);


What is the interpretation of the p-value of 2.2e-16?

I am a beginner in using Wilcoxon test to get the p-value. After applying the test to my data, I got the p-value < 2.2e-16. Does that mean that the samples I have are significantly different from each other? I am suspicious of such a result. I have looked at other related questions (such as  but I didn't really understand what this value means.   Can someone please explain?


Unity3d texture size different than original png image

While selecting a png image as a texture for a material in Unity, it shows different size (bigger) than the actual file size, why is this so? how can I reduce its effective size to make it perform better without loosing much detail.  Size in windows explorer (825 kb)    and this is same image in Unity texture select window (1.3 MB)


Prove that $C^1[0,1]$ is not complete with norms

I have to show that the $C^1[0,1]$ is not complete with any of these norms:   $\|f\|_{\infty}=\sup_{x\in[0,1]}|f(x)|$ $\|f\|_{*}=|f(0)|+\int_0^1|f'(x)|dx$   My attempt  The right sequence for the first norm is $f_n=\sqrt{x+\frac{1}{n}}$.   Notice that $\forall n\in\mathbb{N} : f_n\in C^1[0,1]$  Let $f=\sqrt{x}$  We see that $(f_n)$ converges to $f$ in sup norm in $C[0,1]$, thus it is Cauchy.  $C^1[0,1]$ is a subspace of $C[0,1]$ and all terms of $(f_n)$ are in $C^1[0,1]$, so $(f_n)$ is Cauchy in $C^1[0,1]$  But $f$ is not in $C^1[0,1]$. So $C^1[0,1]$ with sup norm is not complete.  When it comes to the second norm, I think the same sequence will be also okay. Am I right?


I have tried to apply dark themes from Ubuntu 14.04 on 16.04 and they do not come out entirely as expected (different colours and such). What native dark themes for Ubuntu 16.04 are out there? I would prefer a theme retaining the default Unity decorations and icons and simply tweaking colours, but other suggestions are welcome.


Okay, I am stuck.  I have an Ubuntu LiveUSB installed.  Per gparted, it is Partition Table: msdos, File system fat32, mount point /cdrom.  I created the LiveUSB from Windows.  What I'd like is a full installed and independently bootable Ubuntu USB -- not a live, not a persistent, but a full install.  And bootable (added) at least from UEFI computers.   I understand an ext4 is not recommended because of journaling.     How can I make this happen?  I've tried:    gparted the USB to partition msdos, but "Install Ubuntu 16.04.1 LTS" says must install on an ext partition -- will not allow installation on a FAT32 partition. dozens of options trying gpt partition tables with Install Ubuntu, but nothing seems to work. Installation through Install Ubuntu, then trying to push grub on the /fat32 partition.   Can anyone help?


Installation of NVIDIA 367.44 for GTX 970 on Ubuntu 16.04

I give my installation method below.  Basically cannibalized from older posts on other drivers for older Ubuntu releases.  The purpose of this question is three fold:   Learn the preferred way of installing the driver mentioned in the header of this post for the hardware in the header of this post. Learn pros/cons of my current approach Document my approach as there doesn't seem to be a clear post for my particular hardware/Ubuntu combination to aid others in a similar situation   Some context  I'm setting up a Deep Learning environment on my machine so am currently going through the pains of setting up the host machines driver and then will move on to installing nvidia-docker and so on.  My installation method:   Download latest long lived release (367.44):  sudo apt install nvidia-modprobe Restart At login prompt: ctrl-alt-F1 for tty Login with credentials sudo service lightdm stop sudo init 3 cd ~/Downloads chmod u+x [Nvidia installer here].run sudo init 3  sudo ./[Nvidia installer here].run  Ignore errors about pre-install script failing and 32 lib target  install location not found.  If there are errors saying that nouveau is still in use (after  being blacklisted) then might be necessary to update the initramfs  disk, so then do:   sudo update-initramfs -u   reboot   A black screen will be present on reboot instead of normal Ubuntu  splash screen.  Repeat steps 3 and on.  Ignore step 9 (only necessary once).  Not sure if step 7 is needed again I had to do two iterations  starting from step 3 and on since sudo init 3 seemed to actually  start the X server so I was getting an “X server is running” error  during install of .run file.  So on second iteration (and  consequently second reboot) I left out step 7 and it seemed to  work. sudo service lightdm start sudo reboot Log in and check: System Settings -> Details -> Graphics Should  read something like “GeForce ...” (assuming you have a GeForce  series GPU) In my case: “GeForce GTX 970/PCIe/SSE2” NVIDIA X Server  Settings -> NVIDIA Driver Version Should read “367.44”   Addendum:  I did see an Xorg error on startup/login: “Xorg crashed with SIGABRT in RRSetChanged()”. It seems that this is a known bug for Nvidia gpus and doesn’t seem to be critical.  Questions:   I see that it "may" be possible to accomplish this installation via ppa:graphics-drivers Reference:   Would this have accomplished the very same thing as my installation method and how does it compare (pros/cons) to mine above? Even though my installation above seems to have been successful, I'd like to know what pros/cons exist due to my approach and what (if any) issues might arise from my approach as I continue to install my Deep Learning environment (e.g. nvidia-docker, theano, keras, etc)?


Why isn't energy conserved in this collision problem?

I am stuck in a question where energy conservation is failing and momentum conservation is correct. I think I might be doing something wrong, that's why I'm asking this question. The problem is as follows:     A bullet of mass $25\,g$ is fired horizontally into a ballistic pendulum of mass $5.0\,kg$ and gets embedded in it. If the centre of pendulum rises by a distance of $10\,cm$, find the speed of the bullet.   (H.C. Verma, Centre of Mass, Q47)     Let the mass of the bullet be $m=25\,g$. Let the mass of the pendulum be $M=5\,kg$. Let the peak height be $h=0.1\,m$. Let the initial and final velocities be $u$ and $v$ respectively.  Method 1: (Momentum Conservation)  $$mu=(M+m)v \implies v=\frac{mu}{M+m}\\ \text{Also, }\frac{1}{2}(M+m)v^2=(M+m)gh\\ \implies u^2=2\biggl(\frac{M+m}{m}\biggr)^2gh\\ \implies u=201\sqrt2 \text{ m/s}$$  Method 2: (Energy Conservation)  Since both the masses move together after the collision, and because the velocity at highest point is null, therefore: $$\frac{1}{2}mu^2=\frac{1}{2}(M+m)v^2=(M+m)gh\\ \implies u^2=2gh\biggl(\frac{M+m}{m}\biggr) \implies u=\sqrt{402}$$    To summarize myself, I am curious about the following: Why do the results differ? Shouldn't the energy be conserved as well as the momentum? Since it should be, then what is the flaw in my calculations?


There seems to be an issue with the flair link. On any site, after going to the user profile page, if I click on the flair link, its is not taking me to the flair page. Instead it stays on the same page with the URL of the page changes to this    This seems to be a bug where an extra / is added to the URL.  Update: As  pointed out, it seems that because of the characters in my username, the URL is not getting generated properly. But I'd like to point out that, if such characters are allowed to be entered as a part of the username, then the system should handle them as well.


Let $I_n=\left(\frac{1}{n},1\right)$. Show that $(0,1)$ is not compact: show that any finite collection of $\{I_n\}$ will not cover $(0,1)$.  Give me a hint.


How to prove that $\varphi\left(mn\right)=\varphi\left(m\right)\varphi\left(n\right)$

Of course we are familiar with the notion that if $n=p_{1}^{k_{1}}\cdots p_{r}^{k_{r}}$ ($p_{i}$ distinct primes; $k_{i}>0$), then $$\varphi\left(n\right)=n\left(1-1/p_{1}\right)\left(1-1/p_{2}\right)\cdots\left(1-1/p_{r}\right),$$ where $\varphi$ is the Euler totient function.  The goal is to prove this using the fact that $\varphi$ is multiplicative, that is, $$\varphi\left(mn\right)=\varphi\left(m\right)\varphi\left(n\right),$$ given that $m$ and $n$ are coprime.  Proving the former notion from the multiplicative property. But how do we prove the multiplicative property of $\varphi$ without using that notion?


I've been trying to prove the following:  Lets have a function continuous and derivable for any x that belongs to the real numbers; and for any $x$ and $h: f(x+h) -f(x) = hf'(x)$.  So, I have to prove that $f(x)= ax+b$, where a and b are constants. I tried to use the Mean Value Theorem because it has its similarities but I kept getting nowhere. It is obvious that the function satisfies the equation but that ain't a proof. Thanks.


I have the following error in Java code and cause my application to crash. This error is due to the imageView being null.      Error:Caused by: java.lang.NullPointerException: Attempt to invoke   virtual method 'void   android.widget.ImageView.setClipToOutline(boolean)' on a null object   reference at   ir.nasim_velayat.sorud.activity.Main2Activity.onCreate(Main2Activity.java:91)   And Java Codes:  Line 90 : imageView = (ImageView) findViewById(R.id.img_news_top); Line 91 : imageView.setClipToOutline(true);   I anticipate that this error is due to the fact that I have not set the imageView correctly, but I do not know how to set it correctly.  xml Code(ImageView):  <ImageView             android:id="@+id/img_news_top"             android:layout_width="280dp"             android:layout_height="150dp"             android:src="@drawable/bg_header"             android:background="@drawable/shape_radius"             android:scaleType="centerCrop"             android:layout_centerInParent="true"             />


Can you activate more than 2 magic rings in one turn?

The idea stems from one of my players but can you tie magic rings (enchanted with magic missile) together and activate them all in one action? So for example they have ten magic rings all with the same spell, can he use all the rings as they are tied together (essentially creating a single object.)


I have a problem with perfboard, every time I made a circuit which works flawlessly in breadboard, doesn't work on perfboard. Is it because of soldering distance or am I doing something wrong?  All circuits are 5-12V and low current (200mA max). First one is 7 segment display, second one pwm motor control, last one Ne555 frequency generator. Display circuit's problem is display randomly flickers segment. PWM's problem is MOSFET randomly opening or closing (and heats up). NE555 problem is output is always on even NE555 removed.   It seems like solder or perfboard causing the voltage jump (somehow) but I checked several times and multimeter shows no connectivity, I tried to clean the paste and clean the space between solders but still no luck. Some of my circuits to show the problem:


cp -Rdfp $source/* $dest/ wont copy .htaccess

This command wont copy .htaccess files:  cp -Rdfp $source/* $dest/    Thanks


I'm Trying to convert this xml to array saving the attributes names. Because I need to send this parameters to a Client using Wcf, and the client needs to display that information  <?xml version="1.0" encoding="utf-8" ?> <Configuration>   <Cameras>    <Camera Name="Camera1" Url="Camera1" Width="600" Height="800" />    <Camera Name="Camera2" Url="Camera2" Width="600" Height="800" /> </Cameras> </Configuration>   I'm using C#


What should I know about C# before walking into an interview for a .NET job?

Sure, we all have written tons of C# code. So walking into an interview for a .NET job should be a no-brainer, right? And then you read some stackoverflow posts and it hits you: You don't know squat!  Remember that site with the cram sessions to go through, before taking an exam? I think stackoverflow could be used to make a sorted (voting) list of topics to know about.  Please only put one topic per post. Please also add some information about the topic. Links, reference material etc.  EDIT: I guess some of you misunderstood the reason for the post - I'm hoping to generate a list of stuff to know about .NET, a sort of cram session that can be reviewed by everyone on the planet to regularly review. This should help us all remember arcane stuff we never really use.


Is there a limit to the number of attempts to logon to an iPhone 8?

A relative managed to change her password, yet can not input the correct password.  She does not want to reset the phone to avoid loss of data (pictures, contacts, messages, etc.).  Will the phone eventually stop accepting logon attempts?


Rolling a die until we have all the numbers- variance

We roll a die until we obtain all numbers from $1$ to $6$. I found the expected value of rolls computing it like $X = X_1 + \dots + X_6$ where $X_i$ is number of rolls needed to obtain a result different from previous $i-1$ and using a geometric distribution. And my result is correct. But then I wanted to find a variance. Firstly I thought of doing it this way: $$\text{Var} (X_1 + \dots + X_6) = \text{Var}(X_1) + \dots + \text{Var}(X_6) + 2 \sum_{1\le i<j\le6} \text{Cov}(X_i, X_j),$$ but covariance is not easy to find here. Can somebody please show me how to find a variance of number of dice rolls?


I am running Windows 7 on my main machine, however I have installed Mac OS X Mavericks to a VirtualBox VM (on another hard drive) which I am tend to be using a fair bit.  The VM is fully setup and working, and I want to make the OS X VM as my main OS, so when I boot up my PC, it will boot into my Mavericks OS instead of Windows.   My plan is to use the hard drive that already has Mavericks installed, and put it into my PC, so effectively I have one hard drive in my machine that is running Mavericks.  Is there any way to convert a VDI (Virtual Disk Image) to run as a Primary OS? If any of this even makes sense.  Thanks in advance!


One of my objects won't show in my F12 or final render

I've tried to render my scene but there's an object that won't show up. I've checked the camera, I've checked the visibility, it isn't hidden and it's showing in the viewport. I feel like I've opened every setting and have achieved nothing. I’m trying to render a book with a cover, flipping pages and stacks of pages. I have no idea how to fix the fact that the book cover doesn’t render. If I create a plane and select both the book cover and the plane and join them with Ctrl+J, the render contains a book cover but it doesn’t turn as it’s rigged to do so because it’s now linked to the plane and loses all the animated properties. As soon as I unjoin them the book cover stops rendering and everything appears as you see it there, a book with binding, pages, but no cover. For the life of me I cannot figure out what’s going on. Here is an image of what I want it to look like with the insufficient fix:  Here is an image of what it comes out like:  Here is an image of the settings in my project:  Here is an optional link to my project:


Finding the time required for an object to move from point A to B when the Force exerted is a function of distance? (Proportional to the inverse sqr)

I know we will have to use double integration. But I need some help in making and solving the equation. The example of these scenarios is the time taken for an object falling towards Earth from Infinity. PS: I have formal mathematical knowledge till Calculus BC only. So, if you use higher level mathematical tools, please name them so I can look them up.


Get e-mail addresses from Gmail messages received

How can I export a list containing e-mail addresses for everyone that has sent me an e-mail?  I have all of the messages archived.


Accessing Spatial Analyst extension from stand alone script?

If I run this script:  import arcpy arcpy.AddMessage(arcpy.CheckExtension("Spatial")) from arcpy.sa import Con from arcpy import env fDir=r'd:\scratch\fdir' outFolder=r'd:\aerials\images' env.workspace = outFolder fDir=arcpy.Raster(fDir) Gter=Con(fDir> 1,2) Gter.save("TEST")   from ArcGIS, the output is:    When I run it as stand-alone script, it is very different story:    How do I access Spatial Analyst extension from a stand alone script?


What does this syntax mean: paths = [line[2:] for

My using python only occasionally; so I understand the basic concepts; but today I ran into a piece of code ... that I simply don't understand:  I was looking for an efficient way to do "find" via python; and this  shows this answer:  paths = [line[2:] for line in subprocess.check_output("find . -iname '*.txt'", shell=True).splitlines()]   And yes, it works for me; and is much faster compared to os.walk; so I intended to use it. But I have to admit: I don't understand what it is doing; especially the 'line[2:]' part ... wtf?!  I tried to use google/so to find the answer; well, searching for "python line" didn't help at all ... so, probably stupid question: what does it mean?


Pythagorean triple $(\xi,n,\zeta)$,prove that at least one of the numbers are divisible by $3,5$

Let a Pythagorean triple $(\xi,n,\zeta)$.Prove that at least one of $\xi,n$ is divided by $3$ and that at least one of $\xi,n, \zeta$ is divided by $5$.  That's what I have thought:  We suppose that : 1)$\xi=3n+1 \text{ and } n=3m+1$  2)$\xi=3n+1 \text{ and }n=3m+2$  3) $\xi=3n+2 \text{ and } n=3m+2$  and we show that at no of the above cases it is possible that $\xi^2+n^2=\zeta^2\text{ ,because the remainders will be } 2,8,9, \text{ but  the only possible remainders that can give } n^2,\text{ divided by } 9, \text{ are } 0,1, \text{ so it is a contradicton.}   $  Similarly,we can show that at least one of $\xi,n, \zeta$ must be divisible by $5$.  Is the way I thought right??  Is there also an other way?


What is the difference between TISE and TDSE, physically , how to visualize it?

I am asking that we are solving the se for time dependencies and independence but what does they mean actually what are we getting actually when we solve them?


I'm traveling to LA for the day and want to do some sightseeing before taking a cruise.  What can I do with my luggage?


UK Visa Application Following a previous Refusal: Changes to the answers on the form

Can we make changes in uk visa new application form for reapplying for tourist visa after refusal of visa? Do they compare previous application with the new application?      Additional info from comments which explain the corrective measures (edit by Gayot)  My college letter clearly says that i am enrolled in 4 years program and he has completed 3 years and 1 more year to go.I will also attach my exam results to prove the number of semesters i have cleared. The letter also says that i want to travel to uk during my vacation as the college is having holiday from 2 june to 4 july 2016 and the college has no objection. I have also attached bonafide letter from college. My Father has savings of 2900 pounds and mother has savings of 1600 pounds.  I have a joint account with my father worth 1500 pounds and we are also showing my fathers fixed deposits worth 12000 pounds. And public provident funds worth 5600 pounds in my name,fathers and mothers name combined.That should be enough?    For those having a problem with the poor resolution of the scan, it is all very standard formulae...  First dot point: she accepts that the cousin has the capacity to provide accommodation, but she needs to evaluate his (the applicant's) personal circumstances (standard text for sponsored applications)  Second dot point: she explains that he is a student with GBP 1k to spend, but she doubts his financial capacity is sufficient and notes that he did not provide sufficient evidence (standard text for student applicants).  Third dot point: she explains that the father sponsor is diving deep into his life savings to pay for the trip. (standard text for disproportionate expenditure)  Last dot point: based on all of that she thinks he will go underground and try to live in the UK (V 4.2 (a) & (c)) and moreover will become reliant on public funds (V 4.2 (e)). Text straight from the manual.  (edit by Gayot)


Is it worth pre-booking for Vatican Museums etc.?

I've seen a link suggesting that  to some of the attractions connected to the Vatican City.  I'm not sure if it's just a way to lock me into paying for something that is equally easy/cheap to do while on-site.


Why, intuitively, is the order reversed when taking the transpose of the product?

It is well known that for invertible matrices $A,B$ of the same size we have $$(AB)^{-1}=B^{-1}A^{-1} $$ and a nice way for me to remember this is the following sentence:     The opposite of putting on socks and shoes is taking the shoes off, followed by taking the socks off.   Now, a similar law holds for the transpose, namely:  $$(AB)^T=B^TA^T $$  for matrices $A,B$ such that the product $AB$ is defined. My question is: is there any intuitive reason as to why the order of the factors is reversed in this case?   [Note that I'm aware of several proofs of this equality, and a proof is not what I'm after]  Thank you!


Instantiating classes in constructor vs in a method

I'm writing a plugin, and for the most part I'm following the  with the addition of autoloading and namespacing.  When running the main class, where you include methods to run in the constructor  function run_plugin_name() {     $plugin = new Plugin_Name();     $plugin->run(); } run_plugin_name();   in the Plugin_Name class we have  class Plugin_Name {      protected $loader;      protected $plugin_name;      protected $version;      public function __construct() {         if ( defined( 'PLUGIN_NAME_VERSION' ) ) {             $this->version = PLUGIN_NAME_VERSION;         } else {             $this->version = '1.0.0';         }         $this->plugin_name = 'plugin-name';         $this->load_dependencies();         $this->set_locale();         $this->define_admin_hooks();         $this->define_public_hooks();     } }   I am wondering what is the best practice, and if there is any benefit if I define the objects that will be used in the add_action / add_filter methods inside the constructor like  public function __construct() {     if ( defined( 'PLUGIN_NAME_VERSION' ) ) {       $this->version = PLUGIN_NAME_VERSION;     } else {       $this->version = '1.0.0';     }     $this->plugin_name = 'plugin-name';      $this->admin = new Admin( $this->plugin_name, $this->version );      $this->load_dependencies();     $this->set_locale();     $this->define_admin_hooks();     $this->define_public_hooks(); }   and then use this inside, say define_admin_hooks() method  private function define_admin_hooks() {     $this->loader->add_action( 'admin_enqueue_scripts', $this->admin, 'enqueue_styles' );     $this->loader->add_action( 'admin_enqueue_scripts', $this->admin, 'enqueue_scripts' ); }   Or should I do it like it's done in the plugin boilerplate  private function define_admin_hooks() {     $plugin_admin = new Admin( $this->get_plugin_name(), $this->get_version() );     $this->loader->add_action( 'admin_enqueue_scripts', $plugin_admin, 'enqueue_styles' );     $this->loader->add_action( 'admin_enqueue_scripts', $plugin_admin, 'enqueue_scripts' ); }   The reason I'm asking is because I have several methods where I add my actions and filters, based on the plugin functionality, and there are some classes that I'm using in both methods. So it seems better to have them in the constructor and then just use them in the methods.  That way I'm not breaking the DRY principle.  Is my reasoning correct?


How to use a definite integral to find the following limit: $\lim\limits_{n\to\infty}\left(\frac{1}{n+1}+\frac{1}{n+2}+...+\frac{1}{n+n}\right)$  Which is equal to $\ln(2)$. I know that there are a lot of series which converge with radius of convergence 1, so I'm assuming i'd have to use this fact in order to integrate the series, but I have no idea what to do here. If someone could drop a hint that would be great


I’m Spanish but sometimes see TV shows in English.  My question is whether the words horse and whores sound exactly the same, because in many English language TV shows it seems like they are, which really surprises me.   Are they homophones?  I cannot hear any voicing at the end of the word whores to distinguish the two words.


I would like to improve the appearance of citations as footnotes. I attach the minimal code, containing an example of what I get and of what I would like to end up with:  \documentclass[10pt,a4paper,oneside]{article} \usepackage[utf8]{inputenc}  \usepackage[ style=footnote-dw, backend=bibtex, autocite=footnote, singletitle=false, doi=false, isbn=false, url=false, date=year ]{biblatex} \DeclareFieldFormat{pages}{\mkfirstpage{#1}} \addbibresource{\jobname.bib}  \usepackage{filecontents} \begin{filecontents}{\jobname.bib} @article{Article1, Author = {Alice, A. and Bob, B. and Charlie, C.}, Journal = {Nature}, Month = {01}, Number = {456}, Pages = {1234-1239}, Publisher = {MyPublisher1}, Title = {Title1}, Volume = {123}, Year = {2000}}  @article{Article2, Author = {Alice, A. and Bob, B. and Charlie, C.}, Journal = {Nature}, Month = {02}, Number = {789}, Pages = {1234-1239}, Publisher = {MyPublisher2}, Title = {Title2}, Volume = {987}, Year = {2000}} } \end{filecontents}  \begin{document}  \noindent What I see is:  I want to cite \cite{Article1}, then both \cite{Article1,Article2}, put footnotes\footnote{This is a footnote}, cite them again\cite{Article1,Article2}.  \vspace{20mm} \noindent I would like things to appear as:  I want to cite$^{1}$, then both $^{1,2}$, put footnotes$^{3}$, cite them again$^{1,2}$.   \vspace{10mm} \noindent or as:  I want to cite$^{[1]}$, then both $^{[1,2]}$, put footnotes$^{[3]}$, cite them again$^{[1,2]}$.   \vspace{10mm} \noindent with in the foot:\\ $[1]$ A. Alice, B. Bob and C. Charlie, "Title1",  Nature 123, 1234 (2000).\\ $[2]$ A. Alice, B. Bob and C. Charlie, "Title2",  Nature 987, 1234 (2000).\\ $[3]$ This is a footnote  \end{document}   Do you have any suggestions?


Combinatorial proof of $2 \cdot 3^0 + 2 \cdot 3^1 + 2 \cdot 3^2 + \cdots 2 \cdot 3^{n-1} = 3^n-1$

I'm having trouble combinatorially proving: $$2 \cdot 3^0 + 2 \cdot 3^1 + 2 \cdot 3^2 + \cdots 2 \cdot 3^{n-1} = 3^n-1$$  I understand that the right hand side can be expressed as the number of possible n-length strings from an alphabet {a,b,c}, minus some specific string, such as "abc".   I see also that the left hand side is a finite geometric series where a = 2 and r = 3 and that I can algebraically prove its sum to be $3^n - 1$.  But how can I prove this combinatorially? How can I show the geometric series to be an answer to the same n-length string problem as the right side, if that is the correct interpretation for the proof?


JasperReports unable to export PDF files

I'm trying to write simple code to export JasperPrint to pdf file. To be precise, write bytes into HTTP response.  My simple code looks like this:  public static void writePdfReport(final JasperPrint jp,                                   final HttpServletResponse response,                                   final String reportName) throws IOException, JRException {     response.setContentType("application/pdf");     response.setHeader("Content-disposition",             "inline; filename=" + (reportName == null ? jp.getName() : reportName).replace('"', '_') + ".pdf");      final OutputStream outStream = response.getOutputStream();      final byte[] pdfBytes = JasperExportManager.exportReportToPdf(jp);     response.setContentLength(pdfBytes.length);      final ByteArrayInputStream bais = new ByteArrayInputStream(pdfBytes);     IOUtils.copy(bais, outStream);      outStream.flush();     IOUtils.closeQuietly(outStream); }   My Maven pom file:   <dependency>             <groupId>net.sf.jasperreports</groupId>             <artifactId>jasperreports</artifactId>             <version>6.8.1</version>         </dependency>         <dependency>             <groupId>net.sf.jasperreports</groupId>             <artifactId>jasperreports-fonts</artifactId>             <version>6.8.1</version>         </dependency>         <dependency>             <groupId>ar.com.fdvs</groupId>             <artifactId>DynamicJasper</artifactId>             <version>5.1.2</version>         </dependency>   The problem is that whenever I call writePdfReport function, I get this exception:  java.lang.NoClassDefFoundError: com/lowagie/text/pdf/FontMapper      at net.sf.jasperreports.engine.JasperExportManager.exportToPdf(JasperExportManager.java:214)     at net.sf.jasperreports.engine.JasperExportManager.exportReportToPdf(JasperExportManager.java:544)     at com.kendaxa.fexcom.core.reports.ReportWriter.writePdfReport(ReportWriter.java:31)     at com.kendaxa.fexcom.core.reports.GenericTableReportSpec.Should generate simple table PDF report(GenericTableReportSpec.groovy:100) Caused by: java.lang.ClassNotFoundException: com.lowagie.text.pdf.FontMapper     at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583)     at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)     at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)     ... 4 more   I did my research, first, it seems that the problem is in the JasperReports library suggested here (4 years old):   However, applying an accepted answer does not help, even with the newest version I get the same error.  I've also tried a different approach for exporting files inspired from here  without any luck.  Does anyone have an up-to-date working solution for exporting pdf files? Thank you for any hep.


Cannon Locations in New Super Mario Bros. Wii?

In Super Mario Bros. Wii, there are cannons on the overworld map that you can use to skip worlds. However, the cannons are initially inaccessible, and you need to complete certain levels in a specific manner to get to them. What levels do I need to complete in order to access these cannons?


When $\theta =-\frac{1}{2}$ the Clayton copula is given by $C(x,y)=(\sqrt{x}+\sqrt{y}-1)^2$. I've been asked to show in this case that Kendall's tau is $-\frac{1}{3}$. Using $$\rho_{\tau}=4 \int_0^1 \int_0^1 C(x,y)dC(x,y)-1=4 \int_0^1 \int_0^1(\sqrt{x}+\sqrt{y}-1)^2\frac{1}{2 \sqrt{xy}}dxdy-1$$ I find that $\rho_{\tau}=\frac{1}{3}$. I've done the integration twice by hand and once using Mathematica and always get $\frac{1}{3}$. Am I making some kind of mistake or is the question stated wrong?


Convergence of $\sum _{n=1}^{\infty }\left\{ 1-n\log \frac {2n+1} {2n-1}\right\} $

I am investigating the convergence of  $$\sum _{n=1}^{\infty }\left\{ 1-n\log \frac {2n+1} {2n-1}\right\} $$ Now as per Cauchy's test for absolute convergence.  If $\overline {\lim _\limits{n\rightarrow \infty }}\left| u_{n}\right|^{{1}/{n}} < 1,\sum _\limits{n=1}^{\infty }u_{n}$ converges absolutely  Obviously, if $\overline {\lim \limits_{n\rightarrow \infty }}\left| u_{n}\right|^{{1}/{n}} > 1,\sum _\limits{n=1}^{\infty }u_{n}$ does not converge.  I observed $$\overline {\lim _{n\rightarrow \infty }}\left| \log \left( \dfrac {2n+1} {2n-1}\right) ^{-n}\right|  = \overline {\lim _{n\rightarrow \infty }}\left| \log \left( 1-\dfrac {1} {n-{1}/{2}}\right) ^{-n}\right|$$  Could I take the negative power of $n$ outside the absolute brackets here? I guess even if I could establish $\log$ part converges that would only show that the overall series diverges right. Is that the correct result ? Any alternative lines of attacking this problem would be much appreciated.


Whole screen going black after rendering

I'm using Cycles as render engine for rendering image and when I'm rendering it, my whole screen shuts down that I need to restart my computer. I have Radeon RX 480 8GB as my GPU, tried to use Radeon ProRender from plugin but it doesn't have somes functionalities. Is my GPU too weak ? Really don't want to use Eevee.


How can I configure syslog.conf file, to log iptables messages in a separate file?

How can I configure /etc/syslog.conf file in order to save log information about iptables in a specific file.  I want to save these information separately, so I can extract what I want easily and rapidly.


Python list multiplication: [[...]]*3 makes 3 lists which mirror each other when modified