Suggested edits in top-bar put flags over the winterbash snowflake

Suggested edits in the top bar put the flag count right over the winterbash snowflake. Looks pretty ugly if you ask me...


I have to do proof of $(a+b)^n$ and $(a+b)^{n+1}$ with mathematical induction.  I finished the first one $(a+b)^n = a^n + na^{n-1}b+\dots+b^n$.  I however have trouble with the second one, I don't know what to start exactly. Any help/hints?


Create smaller row from alias and preserve column names

Using Postgres:  SELECT users."name" AS "name"     , array_to_json(array_agg(sites)) as sites FROM remodel.users AS users JOIN remodel.user_sites AS user_sites     ON users.id=user_sites.user JOIN remodel.sites AS sites     ON sites.id=user_sites.site GROUP BY "users".id ;   currently produces  "Toby";"[{"id":1,"name":"Village","created":"2015-08-10T15:22:36.622298"},          {"id":2,"name":"Manor","created":"2015-08-10T15:22:43.614551"}]" "Amy";"[{"id":3,"name":"Park","created":"2015-08-10T15:22:48.810872"}]" "Anne";"[{"id":2,"name":"Manor","created":"2015-08-10T15:22:43.614551"},          {"id":1,"name":"Village","created":"2015-08-10T15:22:36.622298"},          {"id":3,"name":"Park","created":"2015-08-10T15:22:48.810872"}]"   however I would like not to have the "id" field in the JSON output.  changing the sites selection to  array_to_json(array_agg(row(sites."name", sites.created))) as sites   causes the fields to lose their names   "[{"f1":"Village","f2":"2015-08-10T15:22:36.622298"},   {"f1":"Manor","f2":"2015-08-10T15:22:43.614551"}]"   and attempting (what would be a horrible) sub selection  , array_to_json(array_agg((SELECT "name", created FROM sites))) as sites   understandably throws an     ERROR: relation "sites" does not exist   And removing the id with a select in the from clause prevents joining the tables.  I'm looking to preserve the column information as well as I can,  not just for conversion to JSON but for inclusion in much larger and complex queries,  so performing the array selection without using JSON is preferred.


study of subspace generated by $f_k(x)=f(x+k)$ with f continuous, bounded..

Let $f:ℝ→ℝ$ be continuous, bounded function such that the space $\mathrm{lin}\{f_k(x)=f(x+k)∣k ∈\mathbb{N}\}$ is finite-dimensional.  Determine an expression of f.  I started with:  Let $P_f(X) = \sum_{k=0}^n p_k X^k$,  the degree is n,and we define f on [0,n] but after I do not know how to continue.   Thank you in advance.


Can someone help me out please? I am writing my cv, and I need a normal, standard footnote. Here is the heading:   \documentclass[a4paper,10pt]{article} \usepackage{eurosym}   \usepackage[bookmarks=false]{hyperref} %make sure it comes last of your loaded packages %\usepackage[dvips,bookmarks=false]{hyperref} %make sure it comes last of your loaded packages \hypersetup{pdfstartview=FitH,pdfhighlight=/O,colorlinks=true,urlcolor=red,linkcolor=red}  \oddsidemargin = 21 pt \evensidemargin = 21pt \textwidth = 410 pt  \usepackage{fancyhdr} \pagestyle{fancy} \usepackage{lastpage} \lhead{Henrique GOMES\hspace{.5em}} \chead{} \rhead{Curriculum \hspace{.5em}   -- \hspace{.5em} Sep 2013} \lfoot{} \cfoot{} \rfoot{{Page \thepage ~of \pageref{LastPage}}} \renewcommand{\headrulewidth}{0.5pt} \renewcommand{\footrulewidth}{0pt}    \setlength\parindent{0in}   And the footnote is in a tabular environment:   \begin{tabular}{ll} aaaa\footnote{aaaa} \end{tabular}


I have to use algpseudocode package to improve my paper look like more professional   But I can't compile successfully.  \usepackage{amsmath} \usepackage{algorithm} \usepackage[noend]{algpseudocode}  \makeatletter \def\BState{\State\hskip-\ALG@thistlm} \makeatother  \begin{document} \begin{algorithm} \caption{AIP}\label{euclid} \begin{algorithmic}[1] \Procedure{MyProcedure}{} \State $\textit{locationAgent} \gets \text{position of }\textit{{agent}}$ \State $\textit{locationMD} \gets \text{position of }\textit{{MD}}$ \If {\textit{distance(eNB,$agent_i$)}}>$\delta$ \BState \emph{loop}: \State $j \gets \textit{patlen}$ \If {$\textit{string}(i) = \textit{path}(j)$}\Return TURE \State $j \gets j-1$. \State $i \gets i-1$. \State \textbf{goto} \emph{loop}. \State \textbf{close}; \EndIf \State $i \gets i+\max(\textit{delta}_1(\textit{string}(i)),\textit{delta}_2(j))$. \State \textbf{goto} loop \EndProcedure


Find html label associated with a given input

Let's say I have an html form.  Each input/select/textarea will have a corresponding <label> with the for attribute set to the id of it's companion. In this case, I know that each input will only have a single label.  Given an input element in javascript — via an onkeyup event, for example — what's the best way to find it's associated label?


Prove that for fixed positive integers k and n, the number of partitions of n is equal to the number of partitions of 2n+k into n+k parts.


First off, I'm kind of out of my element when it comes to formulas and figuring out how to come up with a formula for what I need. If you need any other information, let me know and I'll add it.  Scenario:  I need to determine the opacity percentage of these elements that I'm plotting on a map. Now, my scale of 0-100 is really 0.05-0.85. It's relative to the number of days since an event has happened. Meaning, if an event happened 0 days ago, the opacity should be 0.05, and if an event happened 365 days ago, the opacity should be 0.85. How do I form a formula to get the values in between?


I created this function to fetch the contents of a url with curl  function leggiUrl($url){     $ch = curl_init($url);     curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);     curl_setopt($ch, CURLOPT_BINARYTRANSFER, true);     curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/4.0 (compatible; MSIE 5.01; Windows NT 5.0)");     $content = curl_exec($ch);     curl_close($ch);     return $content; }   if I enter a URL whose content is partly generated by a script JavaScript, this text is taken from the function. I would like to grab the text (finished) of any page. Thank you.


The tag bar's placeholder text is snipped, and only shows “Typ” (or rather, “Ty” and half a “p”):    Firefox and Chrome latest on Mac latest.


Can more than one net be used on a creature? If so, how does a creature escape?

If the first party member uses inspiration to land a net, the rest of the party can throw their nets without disadvantage. Would a single strength check remove all nets?


How can I add text in a non-english language?

How can I add text with non Latin characters? I'd like to get text in other languages like Arabic, Russin (Cyrilic), Japanese, Chinese, Malayalam among others, but I get rectangles instead of Arabic letters.


What is the difference between delegated authentication and single sign-on (SSO)?

On the  for Salesforce Certified Identity and Access Management Designer, it says that you should be able to  Describe the configuration requirements of delegated authentication in Salesforce.  As I've been researching, SSO has been brought up quite a bit. There is obviously an overlap between delegated authentication and SSO. I get the impression the exam guide should say  Describe the configuration requirements of delegated authentication single sign-on (SSO) in Salesforce.  Are delegated authentication and SSO the same thing? Can there ever be an instance when working with delegated authentication that you are not using SSO?


Maximum temperature laptop internals can handle? Cooling options?

So I have a Compaq CQ50-215CA and my sister was using her laptop on her bed and I was just using it quickly to check my email. The surface of the laptop was really hot and I opened Speccy to see that the CPU and GPU temperature was 96 C. A couple months ago, my laptop was on the desk without a cooling pad and I was playing a game. Using GPU-Z back then, I had a reading of 104 C. Even with a cooling pad on a desk, running several processes/games keeps me around 88-90 C.  Is this normal for a laptop and what's the highest temperature the internals can handle? Besides a cooling pad, are there any other more effective ways of cooling a laptop?


What do the Rings of Power actually do to the races that wear them?

So, I've been reading Lord of The Rings, and other Tolkien books, and I've always wondered something. What did the other rings of power, given to the various races by Sauron actually do?


Fixing a code to highlight formulas and text on several lines

In  I've found the following amazing code to highlight text on several lines.  The problem is that code dosen't work well with formulas : for example, fraction using the mode display are partially out of the highlighting frame.   Here is the code with one content showing the problem.  \documentclass{article}     \usepackage{soul}     \usepackage{tikz}     \usetikzlibrary{calc}     \usepackage{amsmath}     \usepackage{xcolor}      \makeatletter         \newcommand{\defhighlighter}[3][]{%             \tikzset{every highlighter/.style={color=#2, fill opacity=#3, #1}}%         }          \defhighlighter{yellow}{.5}          \newcommand{\highlight@DoHighlight}{             \fill[                 outer sep = -15pt, inner sep = 0pt,                  every highlighter, this highlighter              ](                 $(begin highlight)+(0,8pt)$) rectangle ($(end highlight)+(0,-3pt)$             );         }          \newcommand{\highlight@BeginHighlight}{             \coordinate (begin highlight) at (0,0) ;         }          \newcommand{\highlight@EndHighlight}{             \coordinate (end highlight) at (0,0) ;         }          \newdimen\highlight@previous         \newdimen\highlight@current          \DeclareRobustCommand*\highlight[1][]{%             \tikzset{this highlighter/.style={#1}}%             \SOUL@setup             %             \def\SOUL@preamble{%                 \begin{tikzpicture}[overlay, remember picture]                     \highlight@BeginHighlight                     \highlight@EndHighlight                 \end{tikzpicture}%             }%             %             \def\SOUL@postamble{%                 \begin{tikzpicture}[overlay, remember picture]                     \highlight@EndHighlight                     \highlight@DoHighlight                 \end{tikzpicture}%             }%             %             \def\SOUL@everyhyphen{%                 \discretionary{%                     \SOUL@setkern\SOUL@hyphkern                     \SOUL@sethyphenchar                     \tikz[overlay, remember picture] \highlight@EndHighlight ;%                 }{}{%                     \SOUL@setkern\SOUL@charkern                 }%             }%             %             \def\SOUL@everyexhyphen##1{%                 \SOUL@setkern\SOUL@hyphkern                 \hbox{##1}%                 \discretionary{%                     \tikz[overlay, remember picture] \highlight@EndHighlight ;%                 }{}{%                     \SOUL@setkern\SOUL@charkern                 }%             }%             %             \def\SOUL@everysyllable{%                 \begin{tikzpicture}[overlay, remember picture]                     \path let \p0 = (begin highlight), \p1 = (0,0) in \pgfextra                     \global\highlight@previous=\y0                     \global\highlight@current =\y1                     \endpgfextra (0,0) ;                     \ifdim\highlight@current < \highlight@previous                         \highlight@DoHighlight                         \highlight@BeginHighlight                     \fi                 \end{tikzpicture}%                 \the\SOUL@syllable                 \tikz[overlay, remember picture] \highlight@EndHighlight ;%             }%             \SOUL@         }     \makeatother   \begin{document}  Lorem ipsum \highlight{dolor sit amet, consectetur adipis-icing elit, sed do eiusmod tempor} incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation \highlight[red]{ullamco $laboris$ nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit} in voluptate velit esse cillum dolore eu fugiat nulla pariatur.  Excepteur sint occaecat \highlight[green, draw=blue]{cupidatat non proident  $\dfrac{789}{7889}$ % The frame is not good for that formula ! suntinculpaquiofficiadeseruntmollitanimidestlaborum. Loremipsumdolorsitametconsecteturadipisicingelitseddoeiusmodtemporincididuntutlabore-etdoloremagnaaliqua.} I suppose I could write some more text here.  \end{document}     Is someone could help me to fix it?


UV map / model turned black on saving - how to recover?

In the middle of touching up a new texture, I pressed save and suddenly my textures all turned black on the model and UV texture - just vanished.  I tried reopening the file in another instance of Blender, I tried to CtrlZ too and it just did this weird patchy thing on my texture.   How do I recover it and what did I do wrong?


Unlike any other site, Area 51's main site is unencrypted, its login forms are partially or wholly insecure and its login forms completely break under the browser extension HTTPS Everywhere. That doesn't happen on any other sites. This is madness Sparta.  Mere months ago Mark Henderson : Let's encrypt all the things. But:   When I use the HTTPSEverywhere extension on Firefox 50.0.2, the login form appears secure until you try to log in, at which point it barfs  Unable to log in with your OpenID provider: <Big Wall of Red Text>   and I can't login. And when I disable the extension I get either an unsecured or only partially secured form, leaving it unclear to me if my PW is being sent in clear text over the intertubes.  Then when I'm logged in the site isn't secure at all.   In case that matters I'm running Linux and it's fully up-to-date with security patches.  Can Area 51 get area defenses (cryptography) actually worthy of the name?


"New favourites" indicator showing more new favourites than I have in total?

This is more of an aesthetic thing than anything else, however, on my profile after I favourited a single question I have a notification stating I have four new favourites:    I only have this one favourite on meta.stackoverflow.com so I would have expected this number to show a "1", if anything. I am interpreting the meaning of this number correctly, aren't I? If so - something isn't working properly but this is an aesthetic issue.


Prove formally that multivariate function has global extrema

Consider the following function: $f(x_1, \dots, x_n) = p_1 \log x_1 + \dots + p_n\log x_n$ subject to the constraint that $\sum_i p_i = \sum_i x_i = 1$. It is also known that $p_i \in [0,1]$ and $x_i \in [0,1]$.  I need to prove formally that the function has global maximum when $\frac{p_1}{x_1} = \dots = \frac{p_n}{x_n}$, i.e, $x_i = p_i$ gives the global maximum.  I can prove this formally for two variables by using the standard first and second derivative test (eliminate one of the variables). I can also verify empirically that $x_i = p_i$ is the global maximum of this function when $n > 2$ but want to prove this formally.   Is there a suitable technique for multivariate functions that I can use?


File Sharing Links, are they allowed, or should they be avoided?

Question has largely already been answered (in above link); I have found further discussion helpful, as clarification on the use of file sharing was difficult to obtain.     With a stack-exchange account answer is it permissible to use a file - sharing site to host files for a solution.    In this example here is 200 plus images and two or three batch files which could be text files. The end idea is to not have a ridiculously long answer, linking to sites that may link rot, and by including the extra scripts to save the user time.   What is the policies for file sharing links, and what is the recommendations?  Prior found considerations:


Can I configure Linux to use a subsection of my monitor?

I have a monitor that has a defect (red star) in a lower section, is it possible to contain the screen to the section above this defect?    I have tried setting the overscan_bottom in /boot/config.txt, but it seems to shrink the the page horizontally (in addition to the intended direction, vertically) trying to preserve the aspect ratio of the resolution, is my guess.  I believe the monitor is 1920x1080, I don't mind going down to a lower resolution because it's for an arcade game emulator.  I am using HDMI output  The OS is Raspbian.


Sweave.sty causing error in verbatim environment?

folks--    The following throws an error, shown below  \documentclass{book}   \usepackage{Sweave}    \begin{document}    \begin{verbatim}   data ds;      infile 'dir_location\filename.csv" delimiter=",";      input varname1 ... varnamek;   run;   \end{verbatim}    \end{document}     Error:  ! Undefined control sequence.   infile '                   dir_location\filename.csv' delimiter=",";   l.362 \end{verbatim}     Occurs with any ' or ` character in verbatim environments.    Any idea what could be causing this?  Or a workaround?  Thanks!


How to enable IPv6 via miredo along with UFW?

Ubuntu provides some good information on how to enable UFW and on how to enable IPv6 with miredo:       But what is missing is information on how to properly configure UFW to let Miredo work, as as soon as I enable UFW IPv6 stops working:  $ ufw disable $ ping6 ipv6.google.com PING ipv6.google.com(2a00:1450:8004::93) 56 data bytes 64 bytes from 2a00:1450:8004::93: icmp_seq=1 ttl=56 time=1886 ms $ ufw enable $ ping6 ipv6.google.com PING ipv6.google.com(2a00:1450:8004::6a) 56 data bytes ping: sendmsg: Operation not permitted   So how do I properly configure both Miredo and UFW together that basic IPv6 is working, but with all other incoming traffic being blocked?


$\exists S \subset \mathbb{R}$ s.t. every $x \in \mathbb{R}$ can be represented as a unique linear combination of numbers with rational coefficients

Prove $\exists$ infinite set $S \subset \mathbb{R}$ s.t. $\forall x \in \mathbb{R}$, $x$ can be represented as a unique linear combination of numbers in $S$ with rational coefficients.  I'm not asking if every vector space has a basis.  I already have that proven in my notes so this is NOT a duplicate.  I have that $\mathbb{R}$ as a vector space over $\mathbb{Q}$ has a basis and therefore by definition of a basis, $\mathbb{R}$ can be represented as a linear combination of some vectors $x_i \in B_i$ multiplied by coefficients in $\mathbb{Q}$, but I don't have that this representation is unique.


How can I include a node reference field in my form?

My module implements () in order to define a settings page:  function MYMODULE_menu() {     $items = array(         'admin/config/system/mymodule' => array(             'title' => 'MyModule settings',             'description' => 'Various settings for MyModule.',             'page callback' => 'drupal_get_form',             'page arguments' => array('__MYMODULE_settings'),             'access arguments' => array('administer site configuration'),             'type' => MENU_NORMAL_ITEM         )     );     return $items; }   That settings page takes it's settings from __MYMODULE_settings():  function __MYMODULE_settings() {     $form = array(         'my_text_field' => array(             '#type' => 'textfield',             '#required' => TRUE,             '#title' => 'Facebook link'         ),         'my_node_field' => array(             '#type' => 'entityreference',             '#required' => TRUE,             '#title' => 'Contact node'         ),         'submit' => array(             '#type' => 'submit',             '#value' => 'Save'         )     );     return $form; }   However when I do this, the "my_node_field" field (of type entityreference) doesn't display.  On the settings form I want to have a setting that points to a node. I'd like to use the "" module for that setting — I already have entityreference installed, and I'm using it to put node reference fields on a handful of my content types.  Looking at entityreference_field_info(), it looks like entityreference defines a field called "entityreference" — shouldn't I be able to use this field?


Let 𝑎 and 𝑏 be positive integers, show that $\gcd(𝑎, 𝑏) \cdot \mathrm{lcm}(𝑎, 𝑏) = 𝑎b$

So far I have tried this:  Let $c = \gcd(a,b)$. We can say that $a = cx$ and $b = cy$ such that $x$ and $y$ are positive integers that are relatively prime. Then we have that $$ab = (cx)(cy) = c(xyc) = gcd(a,b)(xyc)$$ In order to show that $\gcd(𝑎, 𝑏) \cdot \mathrm{lcm}(𝑎, 𝑏)  = ab$, we must show that $xyc = \mathrm{lcm}(a,b)$.  We will prove this by contradiction.  Assume that $z = \mathrm{lcm}(a,b)$ and that $z<xyc.$ We see that $xyc = (cx)y = ay$ and $xyc = (cy)x = bx$. This means that $a\mid xyc$ and $b\mid xyc.$ So, the lcm of $a$ and $b$ must also divide $xyc.$ Since $x\mid a$ and $y\mid b$, we know that $x\mid z$ and   $y\mid z$. So, we can say that $xy\mid z.$  So z = xyn such that n is an integer and we will assume that $n<c$. Since z|xyc, we have that n|xyc. So c = nm where m is an integer greater than 1. So, we have: a = cx = nmx and z = xyn and that nmx|z so m|y b = cy = nmy and z = xyn and that nmy|z so m|x Since m > 1, we see that x and y are not relatively prime which means that $z<xyc$ cannot be true so z=xyc. So, we have that ab = cz = lcm(a,b) ⋅ gcd(a,b)  But I was told this is incorrect. Is there another approach?


I recall that there was a Putnam problem which went something like this:  Find all real functions satisfying  $$f(s^2+f(t)) = t+f(s)^2$$  for all $s,t \in \mathbb{R}$.  There was a cool trick to solving it that I wanted to remember. But I don't know which test it was from and google isn't much help for searching with equations.  Does anyone know which problem I am thinking of so I can look up that trick?


Hot network questions onebox is invisible in chat

I tried to link to the front page of Stack Exchange in chat today—in other words, to the Hot Network Questions list.  :    The white-on-light-blue is quite hard to read!  But it's even harder to read for other users:    As you can see, it's invisible.  White-on-white text!  Please make it visible.


Code behind Data Context is null, even though its values are showing on the page - Windows Phone 8.1

I have a Page which contains a User Control, the Page's Data Context is bound, and so is the Contained User Control. When the Page is displayed, I can see that the User Control in the Page is displaying the values from the element as I would expect, such as Title and Description, however, in the Code Behind on the same User Control, the Data Context is null.. What am I doing wrong?   I need the Data Context so I could edit it's values within the control or change other UI elements within the page. What am I doing wrong here?  MyPage:  xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d" Background="{ThemeResource ApplicationPageBackgroundThemeBrush}" DataContext="{Binding}"   The use of the User Control with that page:  <Grid Grid.Row="1" x:Name="ContentRoot" Margin="19,9.5,19,0">        <local:ucFooControl DataContext="{Binding}"/> </Grid>   Then, where I am seeing null in User Control Code Behind, even though display elements are showing bound items.  public ucFooControl() {     this.InitializeComponent();      if (this.DataContext != null)     {         bar= (Bar)DataContext;         this.DoSomething((bar);     } }


how to get size or count the number of properties of an object?

Is there any method to count number of properties (or size) of an object (don't want to use any loop) ?  Suppose i have an object obj as,  obj={id:'0A12',name:'nishant',phone:'mobile'};   Then is there any method which results 3 in this case ?


Software that distributes the performance load over multiple computers?

I have 4 laptops at home.  I'm only using one of them, so I wonder if there are softwares that distribute the performance load over multiple computers?  Example 1: If I start a compilation process that would be allocated over all 4 computers and cut the compilation time to 1/4.  I'm not looking for a software to use them as only monitors (like MaxiVista), but using their CPU, RAM, Harddrive, CD-ROM, USB to extend my "main" computer.  Example 2: If I plug in an USB-device/insert a DVD in one of these laptops the "main" computer could use it.  This would be something good to use old laptops for.  I think the word for this is computer cluster.  Are there softwares for home users?  I'm using Mac OS X Snow Leopard btw.


Does the Vampire Knight manga have additional story that the anime doesn't?

I've watched the Vampire Knight anime. I really like the story so far but find it frustrating that the anime doesn't finish off the story. I'm trying to figure out if it is worth reading the manga.  Does the manga contain more story than the anime? Does it finish the story off?


I have disabled the global menu and want to put the classic Application/Places/System menu in its place. How would I go about doing that in Ubuntu 12.04LTS?  (Note: I do want to try keeping unity as well as the dock launcher around for now to see if I can get used to that)


Currently, when registering on my site, users are presented with a first name field and a lastname field (plus an email and password field as usual). My reasoning behind this was to encourage users to use their real name, rather than make up a fake one. This seems a bit heavy handed though, so my question is basically this: What can I do to encourage a user to use their real name when registering?


Is it possible to install Ubuntu Phone in old Nokia Smartphones?

I know and still early but I wonder if you can install ubuntu phone (so to speak) in the old nokia smartphones (microsoft). I'm talking about lumia line. I'm a big fan of lumia line and was wondering if you can. Recalling that the lumia and Windows Phone. I saw the Ubuntu Phone can install through the Android.


What is the Fourier transform of the indicator of the unit ball in $\mathbb R^n$? I think it is known as one of special functions, so I would be happy to know which one.


Prove by induction that $(1+x)^n \geq 1+nx$

Prove by induction that $\forall x \in \mathbb{R}, x \geq -1, \forall n \in \mathbb{N},n \geq 0$ that $$(1+x)^n \geq 1+nx$$ First of all I have a problem with x being a real number, how can I use induction over a real number? Can I simply assume that it holds for all $y \in [-1,x]$ and then show that it also holds for $x + \epsilon, \epsilon \in \mathbb{R},\epsilon \gt 0$?  If that were possible I would try to prove over n. Prove the base case for n, use induction over x and then prove the induction step over n.  But I have some problems with the induction step over n.  Assuming that it works for all $l \in \mathbb{N}, l \leq n-1$. I need to show $$(1+x)^n=(1+x)^{n-1}(1+x) \geq 1+(n-1)x+x$$ which basically results in showing that $$z(1+x) \geq z + x$$ for some quantity z, correct?  But then I'd get $$zx \geq x$$, which would obviously depend on the value of z.  I'm kind of confused at this point, any help would be appreciated.


Why does interference pattern remain constant?

In the double slit experiment we have something like this     Light waves from two sources interfere at screen to give us this pattern. To reach the middle (that is a point on the perpendicular bisector) of measurement screen waves will travel equal distances (at sources they are in phase because of the same main source) and hence will be in phase at the middle of the screen and hence a constructive interference will occur.    We can write things a little more mathematically, if at time $t$ the crest of the light wave is at the sources (secondary) then at time $t+nT$ ($T$ is the time period) crests will be at the middle of the measurement screen and hence a maximum will occur. Here, I have assumed, for simplicity, that distance between the source $S_1$ and the middle point M is $n\lambda$.    Now, my question is when there was a crest at $S_1$ and $S_2$ then we had a maximum at $M$, but when there is no disturbance at sources (I mean $E(t)=0$ and $B(t)=0$) then there should be no disturbance at M too and therefore we should obtain a dark fringe (no light) for this particular interference. Why does the interference pattern remains static? The bright fringes should be turning on and off periodically.    My question comes down to normal light also, why do we see the light even when the electric field and magnetic field components reach their zero position periodically? We should see light as being turning on and off, off when $E(t)$ and $B(t)$ becomes zero and on for every other time.    P.S. :- My $M$ in the figure doesn't coincide with the maximum but by $M$ I meant the middle of the screen where the first maximum gonna occur.


How can I show that the duplicate question answers my question?

Very often on SO (and other 'exchanges),  an question of mine is marked as a duplicate.  How can I mark that the question I duplicated answers my question? Leaving a comment seems like the best way to do this, but comments aren't forever.


Is there or can there be a way to highlight text in an answer?

I have asked a question which has yielded a massive list-type answer.  There are several points within this answer that I would like more information about, but placing them all into a comment (which might not even fit) would be really messy / illegible and if someone did this to my answer I probably wouldn't even respond.  Could there be a feature where I as the OP can highlight parts of the answer which will notify the answerer, giving them the option to provide more information about what I've highlighted? The highlights could be yellow but only visible to the answerer (so that while browsing the website there isn't yellow everywhere).  This would be particularly useful for this style of answer, especially because I'd like information on 5 or more of those points.


What is another word for "likes to try new things"

I'm looking for a word to describe someone who likes to try new things. Any suggestions?


Microcontroller and processor same thing or not?

Is it correct to refer to a microcontroller as processor?   I know microcontroller is different than microprocessor. But is it the same as processor?  The whole point of this question is to verify if there is a difference  between these two "definitions": microprocessor and processor core.


How to prove if $u\in W^{1,p}$, then $|u|\in W^{1,p}$?  Since $|u|\in L_p$, I only need to show weak derivative of $|u|$ exists and $D|u| \in L_p$.  Can anyone give me some hint? Thanks!


I created a field field_quantity_description that contains HTML code. I can output the escaped content of this field:  {{ quantity.entity.field_quantity_description.value }}   I want to render HTML inside this field, so I usually use raw filter like this:  {{ quantity.entity.field_quantity_description.value|raw }}   But Drupal 9 tells me that raw is deprecated. But what do I have to use instead to render HTML inside the field?


A namesake is a person that is named after another person.  Is there a word or phrase to describe the reverse relationship?     He is my namesake.  I am his _____.


How do I hide a particular user from the login screen?

How do I hide a particular user from the login screen on a default install of 11.10 and higher? (ie. using Unity Greeter)?


Text editor with syntax highlighting, theme support and code folding

I like  under Windows. I was wondering if there are some similar ones for Ubuntu? Or just the powerful and convenient one in your opinion.  Features that I like are:   syntax highlighting for language X theme support line numbering code folding regex style Powerful, yet not resource-consuming


Getting hybrid graphics to work nvidia-prime GT650M

I recently made the switch to Ubuntu. Everything on my laptop works fine except my hybrid graphics card. It is Intel graphics combined with Nvidia GeForce GT650M. I tried Bumblebee, but primusrun doesn't work (segmentation fault, core dumped) and optirun works with glxspheres64, but steam games look worse with optirun than with Intel graphics (e.g. Surgeon Simulator 2013 runs fine with Intel and hangs a lot with optirun)   I tried Nvidia Prime, but it gives me a black screen on startup after install, so I can't do anything and have to power off my PC with the power button. I also tried nvidia-prime 0.5 on Ubuntu 14.04, and then I get 'low-graphics mode' and I can't get to Unity.


How to align content in all cells in table with images vertically to center

I am quite beginner with LaTeX. I am trying to make one table with 3 columns, where the second column contains images. The rest contains just simple text. My problem is to synchronize contents (text and images) in all cells. I want to align contents vertically to center in all cells.  \begin{table}[!htb] \renewcommand*{\arraystretch}{4} %\setlength\extrarowheight{25pt} \centering \begin{tabular}{|l|c|l|} \hline Continue   &    \raisebox{-\totalheight}{\includegraphics[scale=0.25]  {Figures/Udalosti/eventContinue.png}}&test\\ \hline Born        & \includegraphics[scale=0.25]  {Figures/Udalosti/eventBorn.png}&test\\ \hline Death       & \includegraphics[scale=0.25]{Figures/Udalosti/eventDeath.png}&test \\ \hline Merge       & \includegraphics[scale=0.20]{Figures/Udalosti/eventMerge.png}&test\\ \hline Split       & \includegraphics[scale=0.25]{Figures/Udalosti/eventSplit.png} &test \\ \hline Growth & \includegraphics[scale=0.25]{Figures/Udalosti/eventGrowth.png} &test \\ \hline Contraction & \includegraphics[scale=0.25]{Figures/Udalosti/eventContraction.png} &test \\ \hline  \end{tabular} \caption{Test} \label{tab_evolution} \end{table}     The result is here on the picture. I tried to align contents vertically with raisebox in first row, but as you can see, it doesn't work properly. Text in first and third column is vertically aligned on center but pictures in second column are not. Can you help me? I would be very grateful for any question. Thank you. :)


I want to know can I travel from dusseldorf to UK by train for 1 day only I only have valid Schengen visa.  If yes, what would be the procedure  Thanks


In econometrics, while using Newton Raphson algorithm, why do we use 2nd Order Taylor Expansion, what is the requirement or intiution behind it? Is it something related to convergence issue? Can someone show analytically?


Find and keep matches from 2 columns in Excel

In Excel I have two columns, one with about 3000 rows and one with about 100.  I need to find all of the matches between the two columns and put them in a separate column.  I have to do this every morning so if there is a way to do so, I'd like to make it as automated as possible.


Redirect subdomain to subdomain in HTTPS with Apache2

I have those subdomains:  link.domain.com links.domain.com   I want to redirect the link.domain.com to links.domain.com. For this, I used the same method as described here :  and it works.  I installed a TLS certificate for links.domain.com with Let's Encrypt and I can perfectly access links.domain.com in HTTPS. I would like the redirection from link.domain.com to links.domain.com to be also effective in HTTPS.  Here is my conf file:  <IfModule mod_ssl.c>    <VirtualHost *:443>       DocumentRoot /var/www/links/       ServerName links.domain.com        <Directory "/var/www/links/">          Options Indexes MultiViews FollowSymLinks          AllowOverride None          Order deny,allow          Allow from all       </Directory>        ErrorLog ${APACHE_LOG_DIR}/error_links.log       CustomLog ${APACHE_LOG_DIR}/access_links.log combined         # Possible values include: debug, info, notice, warn, error, crit,       # alert, emerg.       LogLevel warn        SSLCertificateFile /etc/letsencrypt/live/links.domain.com/fullchain.pem       SSLCertificateKeyFile /etc/letsencrypt/live/links.domain.com/privkey.pem       Include /etc/letsencrypt/options-ssl-apache.conf    </VirtualHost> </IfModule>   I already tried the following :   Adding  ServerAlias link.domain.com  RedirectMatch permanent ^link.domain.com/(.*)$ https://links.domain.com/$1  after the ServerName links.domain.com line. Adding  <VirtualHost *:443>     ServerName link.domain.com     RedirectMatch permanent ^/(.*)$ https://links.domain.com/$1  </VirtualHost>  before and after the already defined VirtualHost.   No one worked.  Do you have any idea ?


E45 'Readonly' option is set, vi won't save file changes even with sudo

I am the only user on my laptop. I want to do some changes on readonly .conf file for netbeans and after hit ESC and try to save I get this error E45 'Readonly' option is set. Even though I opened the file using sudo and provided my password. What am I missing?


Ubuntu 17.04 wont install any packages or setups from terminal

hey Dears i cant install any program on my Ubuntu from when i upgrade it to 17.04.  I am not Sure the problem is from the version or my OS please.. replay


I'm having some trouble fully understanding partial correlation and I was wondering if some of you can shred some light on my confusion. Let's consider the following scenario: It is a known fact that heart disease is related to social and economic status. However, I want to understand if Anger is also a factor. So the obvious next step is to find the correlation between Anger and heart disease while controlling for social and economic status. There are a couple ways I can do this. The one popular way that I found online was to use partial correlation (ppcor in R). However, when I looked into how they did partial correlation, it didn't make a lot of sense to me mathematically. The way they do it is: let's say they have 3 variables ($X, Y , Z$) and we want to correlate $X$ and $Y$ while taking into consideration $Z$, they take the residuals from correlating $X$ and $Y$, then $X$ and $Z$, then they correlated the two residuals to get the result. This doesn't make a lot of sense to me, if residuals are variance that are not explained through correlation, then wouldn't it make more sense to only take the residuals from $X$ and $Z$, then correlate that residual with $Y$, that way we can see if $Y$ can explain the variance that is not explained by $X$ and $Z$, therefore "controlling" for $Z$?


Suggestions for cost-sensitive learning in a highly imbalanced setting

I have a dataset with a few million rows and ~100 columns. I would like to detect about 1% of the examples in the dataset, which belong to a common class. I have a minimum precision constraint, but due to very asymmetric cost I am not too keen on any particular recall (as long as I am not left with 10 positive matches!)  What are some approaches that you would recommend in this setting? (links to papers welcome, links to implementations appreciated)


How to completely disable Nouveau, as other tutorials aren't helping?

I'm attempting to install the drivers for my Nvidia GPU by following the steps listed , but after launching the installer it informs me that I must disable the Nouveau kernel driver before installation can continue (There is also an error message displayed before this stating that the 'distribution-provided pre-install script failed', but from what I've read in other posts it shouldn't be a problem to just continue and ignore it?).   Anyway, I've followed the steps listed  in an attempt to disable the Nouveau driver with no such luck. I've run sudoedit /etc/modprobe.d/nvidia-graphics-drivers.conf and populated the file with the given data and saved it, I've edited a line within the /etc/default/grub file so that it now reads GRUB_CMDLINE_LINUX_DEFAULT="nouveau.blacklist=1 nomodset quiet splash", and I've attempted to install the driver from within tty1 by first disabling gdm3 using sudo service gdm3 stop and then using the command sudo sh NVIDIA-Linux-x86_64-384.69.run. Even after doing all this the same error informing me that Nouveau needs to be disabled appears.  I should mention at this point that I used this method of installing the driver once before a few days ago and it worked. For the life of me I can't remember how I got it to work or why it won't work this time around. Also this is essentially a completely fresh install of Ubuntu Gnome 16.04 LTS, the only alterations I've made so far are the installation of Chromium, Discord, a couple of extensions and I've made a few UI changes in the Tweak tool.   So, can anyone offer any more advice on how to disable Nouveau? I feel that if I can get this disabled entirely then I'll be able to install the driver without further issue, but until I can figure this out I can't currently continue using my system because the default Nouveau driver causes the UI to freeze without reason or warning sporadically. In fact it crashed while I was typing this out, lucky for me Chromium saved what I'd written.   Thanks in advance for any help and advice!


How to solve this integral? $I=\int{e^x \Big(2\log x+\frac{1}{x}+\frac{1}{x^2}\Big)dx}$

$$I=\int{e^x \Big(2\log x+\frac{1}{x}+\frac{1}{x^2}\Big)dx}$$ I have tried to use many methods of substitution  But I am aware of a formula  $$I=\int{e^x[f(x)+f'(x)]dx}=e^xf(x)+C$$  but can this formula be applied to the above equation


Subtracting polygon from another in same layer using QGIS?

I need to subtract a polygon from another bigger one, in the same layer.   I have a layer, with a polygon. Inside this polygon I need to edit another polygon, smaller, without overlap.   How can I do this?


Skype on Ubuntu 18.04 issues - doesn't start and logs me out

The Skype app on Ubuntu 18.04 doesn't start when using the Community Theme snap Wayland (communitheme) theme. It automatically takes me to the lock screen    Also, clicking on Skype's file sharing icon freezes the app; after a while it shuts down spontaneously. Drag and drop a file for sharing works.


Where any aliased command is stored? If I am aliasing "ls" as "l" then where will that aliased be stored? Does it affect .bashrc or .cshrc?


How to prove a numerically calculated Riemann zero is exactly zero exactly on the line?

If non-trivial zeroes of the Riemann Zeta function are irrational, and we have to calculate $\zeta[t]$ numerically, how is it ever possible to prove that a particular zero of $\zeta[t]$ falls exactly on the $Re[t]=1/2$  line?  Are we really only able to prove that they're within our computational precision of that line?


I need to write a formula with a \widecheck over two \hat. The equation is the following:  \documentclass[a4paper,11pt]{article} \usepackage{amsmath}  \usepackage{amsfonts,amssymb,mathabx}  \begin{document} \begin{equation} \tilde{A}^\mu_\Lambda = \widehat{\widehat{G}\cdot\widehat{j^\mu_\Lambda}}. \end{equation} \end{document}   If I write this code I obtain a lot of errors (undefined control sequence, missing number treated as zero, illegal unit of measure (pt inserted), etc...).  If I use \widehat instead of \widecheck, the result is the same. I have problems also writing   \widecheck{\hat{G} \cdot j}   because the result is not correct (G is translated to the right and overwrites j).  How can I write the \widecheck?


How to copy text programmatically in my Android app?

I'm building an Android app and I want to copy the text value of an EditText widget. It's possible for the user to press Menu+A then Menu+C to copy the value, but how would I do this programmatically?


Intellij JavaFX vs Java Project for .exe file

I have already a Java Project in Intellij.   I want to make a .exe Java file, but I did not find any solution yet for Java Projects. On the other hand, I have found many youtube videos in which they use a JavaFX Project to create an artifact which they will use to create a .exe file.   One of them is the following youtube video:   My end goal is, that a user just double clicks on the file and a GUI opens. After entering some information the rest of the code should run. The file should be able to run to different windows systems, so this should not only work when installing special packages.  Did I chose the wrong type of project? To that I just read, that JavaFX will be discontinued.  I am confused in so many levels...


How to modify view of sub-directories inside a directory?

Trying to modify the view of a directroy, I prefer this view:    But I hate the right part where we see the info on each app.  Is it possible to modify it to be on default like this (without the information part on the right):


What happens if you sequester a target which has a spell with a duration running on it?

The Sequester spell (PHB p.274) states:     If the target is a creature, it falls into a state of suspended animation. Time ceases to flow for it, and it doesn’t grow older.   If the target has spell effects with a duration in place is that duration suspended or does it continue to run down?


sum of the series: $\cos^3 \alpha +\cos^3 {3\alpha} + \cos^3 {5\alpha}+....+\cos^3 {(2n-1)\alpha}$.

Question: Find the sum of the series:   $$\cos^3 \alpha +\cos^3 {3\alpha} + \cos^3 {5\alpha}+\ldots+\cos^3 {(2n-1)\alpha}$$   The book from which this question was taken says that the answer is $$\dfrac{3\sin{n\alpha}\cos{n\alpha}}{4\sin\alpha}+\dfrac{\sin{3n\alpha}\cos{3n\alpha}}{4\sin{3\alpha}}.$$  My attempt to solve this question: $$\text{Let S be the trigonometric series,}$$ $$\cos {3\theta} = 4\cos^3\theta-3\cos\theta \implies 4\cos^3 \theta=\cos{3\theta}+3\cos\theta$$ Applying formula on $\cos^3\theta$, $$4S = 3\cos\alpha + \cos3\alpha +3\cos3\alpha + \cos9\alpha+\ldots+3\cos{(2n-1)\alpha}+\cos{(6n-3)\alpha}$$ $$4S= 3(\cos \alpha + \cos 3\alpha+\cos5\alpha+\ldots)+(\cos3\alpha + \cos9\alpha+\ldots)$$ Applying the summation of cosine formula, $$4S= 3\frac{\sin{n\alpha}}{\sin\alpha}\cdot\cos{(\alpha+(n-1)\alpha)}+?$$  So my problem is I don't know how to apply the formula for the second series (denoted by '?') for a fixed number of terms $n$ or should I treat it as a general and separate series.  To clarify my doubt again, what I am asking is that would the $(2n-1)$ affect the formula for the second series (denoted by '?').  My working here looks most probably correct but if there is any mistake please correct it.


I am trying to print an array of some prime numbers which are divided by a number, the output I get for this code:      [J@15db9742     How can I print the array I get by the function.  public static long[] primes(int n) {     int count = 0;     long arr1[] = new long[n];     for (int i = 2; i < n; i++) {         boolean prime = true;         if (n % i == 0)             for (int j = 2; j < i && prime; j++) {                 if (i % j == 0) prime = false;             }         if (prime && n % i == 0) {             arr1[count] = i;             System.out.println(arr1[count]);             count++;         }     }      long arr[] = new long[count];     for (int i = 0; i < arr.length; i++) {         arr[i] = arr1[i];     }     return arr; }


Is it possible to set the value of an aura component to an expression dynamically?

For example, is it possible to bind the label of a button to a "myButtonLabel" attribute by adding an expression string like in the following example?    $A.createComponent(         "ui:button",         {             "aura:id": "findableAuraId",         //EXAMPLE:             "label": "{!v.myButtonLabel}",         "press": cmp.getReference("c.handlePress")         },         function(newButton){             //Add the new button to the body array             if (cmp.isValid()) {                 var body = cmp.get("v.body");                 body.push(newButton);                 cmp.set("v.body", body);             }         }     );


Can't unzip .zip files in Xubuntu 12.04 64-bit

I downloaded some .zip files and tried three different programs to open them and these are the results that I got:  Squeeze: command exited with status 2304  Archive Manager: cannot open file as archive  Xarchiver: Archive format is not recognized  So, how am I supposed to open .zip files?


After installing Ubuntu 14.04,I installed kubuntu-desktop so I can choose between unity and KDE. But now the kubutu logo appears when I turn on the computer. How can I restore the ubuntu logo (which appears when the computer is booting up)?


Is there a rule as to when I use "more" in a sentence or "-er"? For example, "I think it would be more fun/funner if we stayed home tonight." I know the correct usage in this sentence but is there a general rule to follow?


I have tried using Plugins to remove 72K comments with no success

I have tried a lot of plugins that say they will remove all the comments with NO luck.   I am still showing a number of 72,037 comments, but I no longer can see the actual comments themselves. And, it's showing them all in 'Pending' with 103 in trash.  This site has been inactive for a couple years and I am just helping out getting it cleaned up for use again. How do I get that number to STOP showing up if I really don't have the comments. And, if I do where are they hiding?  Help please.  I am the Admin for the site in question.


Self-Studying Measure Theory and Integration

As the title says, I'm interested in reading about measure theory and integration theory on my own time, and was hoping for book recommendations, prerequisites, and things like that.  As for my background, I've taken introductory analysis, where we covered the "typical" subjects up until some theorems about differentiable functions.  I'm taking intermediate real analysis now; we talked about metric spaces in general for a while, but lately we've focused solely on $\mathbb{R}^n$. Now we're working towards a proof of the implicit function theorem in $\mathbb{R}^n$.  I haven't learned any of the theory behind Riemann integration, unfortunately. Is it important to be familiar with this first?


The quotient norm on $\ell^{\infty}(\mathbb{N}) / c_0 (\mathbb{N})$ is given by $\limsup_{n \in \mathbb{N}} |x_n|$.

I try to show that the norm on the quotient space $\ell^{\infty}(\mathbb{N}) / c_0 (\mathbb{N})$ is given by $\limsup_{n \in \mathbb{N}} |x_n|$, where $x = (x_n)_{n \in \mathbb{N}} \in \ell^{\infty} (\mathbb{N})$. My attempt is the following:     By definition, the quotient norm $\| \cdot \|_{\ell^{\infty} / c_0}$ is defined as   $$ \| x + c_0 (\mathbb{N}) \|_{\ell^{\infty} / c_0} = d( x + c_0 (\mathbb{N}), 0 + c_0 (\mathbb{N}) ), $$   which can be re-written as    $$ \| x + c_0 (\mathbb{N}) \|_{\ell^{\infty} / c_0} = \inf \{ \| x + y \|_{\infty} \; | \; y \in c_0 (\mathbb{N}) \}. $$   Since $0 = (0,0,...) \in c_0 (\mathbb{N})$, it follows that   $$ \| x + c_0 (\mathbb{N}) \|_{\ell^{\infty} / c_0} \leq \| x \|_{\infty} = \sup_{n \in \mathbb{N}} |x_n|. $$   I thought about using Bolzano-Weiserstrass' Theorem at a certain point, but I am not sure how to obtain the wished equality from here.    Any help is appreciated. Thanks in advance.


Best way to lock out a group once per week

A SSH server I admin is to be allowed login from a group of users all days of week except sunday. How would be your elegant solution to this? Thanks any input on comments or creative +and+ secure answers. It should also kick out logged users. And take care of any means of login, such as passwords or ssh-keys. (Edited as suggested)


Is it ok to enquire the editor about the accceptance chance of a paper which is under review for 1.5 years

I have submitted two papers in a top-tier applied mathematics journal. The first one is a short paper and the second one is a full paper. After 7 months the short paper and after 8 month the full paper got major revision. For the short paper I submitted the revised paper after 5 months. Finally, this paper got rejected after 7 months after I submitted the revision. Therefore it was under review for (7+5+7) months i.e. around 1.5 yr including the time I took for revising the paper. For the second paper I submitted the revised paper after 5 months. After this 5 months have passed. Therefore it is under review for (8+5+5) months i.e. 1.5 year. Will it be ok if I politely ask the editor about the acceptance chance of the full paper. One week back I asked the editor, he told me that they are waiting for one review. After that they will send the decision. Is it ok to request the editor whether he can confirm its acceptance chance ? If they want to reject reject now only, so that I can send to other journals. I will be applying for some jobs now. I need to know this information urgently. I am concerned because from the first round reviews I am very much hopeful about its acceptance. If I pressurize them they may reject it.


What makes this character worthy to lift Thor's hammer, Mjolnir?

After being created and brought to life by a stroke of Thor's lightning      Vision casually passes Thor his hammer without even straining.   I think there was a gasp from the cinema audience at this point, I'm quite confident this was not in the comics.  Why is this character deemed worthy to lift Mjolnir?  I see three possible reasons:      The mind stone, an infinity gem, overpowers/overrides Odin's enchantment     Thors lightning imparts some of his worthiness     Vision is considered worthy by Odin    Which is it it, or is it another option?


When is this correct: 'there are much to'? I was taught that .   But , implies that some uncountable nouns are plural. So when, if ever, is much plural?


Open a new bash with sudo powers without reentering the password

I find very useful to have more terminal tabs in different current working directories. But if I need sudo privileges I need to reenter the password for every shell.  Is there not a way to extend the sudo credential caching to a new shell or terminal, without doing it by default to all tabs?  PS: I do not want a root shell or terminal.


Injection from $\mathbb{N}\to\{0,1\}$ to the set of all monotonic decreasing functions from $\mathbb{N}\to\mathbb{Z}$

I'm trying to think of such an injection, and unfortunately all of those I've thought about are not strictly decreasing. I would love to get some help or clues. Thank you :)


Given an integer $n\geq 1$, it is known that there are only finitely many finite groups with exactly $n$ conjugacy classes.  Question: For $n\geq 3$, does there exists a finite non-abelian group, with exactly $n$ conjugacy classes?


What's the word for sentences like - "There are two kind of people in this world - those who like ice-cream and those who don't"

I know there's a word for it and it probably is similar to oxymoron, but I can't put my finger on it. Edit - The sentences is generally characterised by having binary choices with no added information. i.e Things are either "A" or "not A"


How to make grub2 boot another drive MBR?

My laptop (DELL Vostro 3350) has two hard drives: Main one (/dev/sda), is a ssd mounted on SATA-HDD slot with Ubuntu14.04 (grub2 installed to this MBR). Installed on normaly hd bay  Second on (/dev/sdb), stock hd (with recovery partition etc etc) moved to SATA-ODD slot in place of dvd drive with an adapter  I can not figure out how to boot Windows from grub2. In the past I remember that (maybe with grub1) I could point to second disk mbr and then Windows booted normally.  So my config is:  Disk /dev/sda: 128.0 GB, 128035676160 bytes 255 testine, 63 settori/tracce, 15566 cilindri, totale 250069680 settori Unità = settori di 1 * 512 = 512 byte Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Identificativo disco: 0x0007d87d  Dispositivo Boot      Start         End      Blocks   Id  System /dev/sda1   *        2048   175781887    87889920   83  Linux /dev/sda2       175783934   250068991    37142529    5  Esteso /dev/sda5       175783936   246163455    35189760   83  Linux /dev/sda6       246165504   250068991     1951744   82  Linux swap / Solaris  Disk /dev/sdb: 500.1 GB, 500107862016 bytes 255 testine, 63 settori/tracce, 60801 cilindri, totale 976773168 settori Unità = settori di 1 * 512 = 512 byte Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Identificativo disco: 0xb3e7a9bf  Dispositivo Boot      Start         End      Blocks   Id  System /dev/sdb1            2048      206847      102400   de  Dell Utility /dev/sdb2          206848    30926847    15360000    7  HPFS/NTFS/exFAT /dev/sdb3   *    30926848   167600175    68336664    7  HPFS/NTFS/exFAT /dev/sdb4       167604160   976768064   404581952+   f  W95 Esteso (LBA) /dev/sdb5       167606208   976768064   404580928+   7  HPFS/NTFS/exFAT   Here is my /boot/grub/grub.cfg section of os-prober  menuentry 'Windows 7 (loader) (su /dev/sdb2)' --class windows --class os $menuentry_id_option 'osprober-chain-CC70378A703779F2' { insmod part_msdos insmod ntfs set root='hd1,msdos2' if [ x$feature_platform_search_hint = xy ]; then   search --no-floppy --fs-uuid --set=root --hint-bios=hd1,msdos2 --hint-efi=hd1,msdos2 --hint-baremetal=ahci1,msdos2  CC70378A703779F2 else   search --no-floppy --fs-uuid --set=root CC70378A703779F2 fi parttool ${root} hidden- chainloader +1 }  menuentry 'Windows 7 (loader) (su /dev/sdb3)' --class windows --class os $menuentry_id_option 'osprober-chain-AC7C4EC27C4E86D4' { insmod part_msdos insmod ntfs set root='hd1,msdos3' if [ x$feature_platform_search_hint = xy ]; then   search --no-floppy --fs-uuid --set=root --hint-bios=hd1,msdos3 --hint-efi=hd1,msdos3 --hint-baremetal=ahci1,msdos3  AC7C4EC27C4E86D4 else   search --no-floppy --fs-uuid --set=root AC7C4EC27C4E86D4 fi parttool ${root} hidden- chainloader +1 }   Both give me this message if i selected them on boot menu:  error: no such device: CC70378A703779F2 (or AC7C4EC27C4E86D4) error: hd1 cannot get C/H/S values     Last, but not the least, from my BIOS i cannot change hard drive boot priority, so there's no way to boot /dev/sdb first.  Edit:  this is my blkid  /dev/sda1: UUID="1597fe18-faf5-48a5-b80f-4cbb7f8b896e" TYPE="ext4"  /dev/sda5: UUID="ea6548f1-3004-49ff-8d1d-4c84dfed3a6a" TYPE="ext4"  /dev/sda6: UUID="e24dbc3b-d2da-4a63-97ce-7430cfce9fce" TYPE="swap"  /dev/sdb1: SEC_TYPE="msdos" LABEL="DELLUTILITY" UUID="3030-3030" TYPE="vfat"  /dev/sdb2: LABEL="Recovery" UUID="CC70378A703779F2" TYPE="ntfs"  /dev/sdb3: LABEL="OS" UUID="AC7C4EC27C4E86D4" TYPE="ntfs"  /dev/sdb5: LABEL="VostroHD" UUID="01CCBB70E50A71E0" TYPE="ntfs"   EDIT: I ran bootinfo script.  the result  EDIT2: PC configuration at top


Are "pushforward" and "pullback by zero section" of diffrentials isomorphic in elliptic curves?

Let S be a scheme, $p:E\rightarrow S$ be an elliptic curve with zero section $e:S\rightarrow E$. My question is: Are $p_*(\Omega_{E/S}^1)$ and $e^*(\Omega_{E/S}^1)$ isomorphic? I think it's right because I saw both definitions in different notes and they seem to represent the same thing. Thank you!


Etymology of "boy" as an exclamation/interjection

In the sentence "Boy, is there a lot to answer for" (from a recent ), "boy" is .  How did this meaning/usage come about?  It doesn't seem to be some sort of minced oath, and an association with the pejorative term "boy", used to mean "black male", seems a bit far-fetched.  The suggested dupe fails to satisfactorily explain the origin of the term.  It's easy to explain how "Gee" is a minced version of "God", but I don't see such a pathway for "boy".  And the condescending sense suggested doesn't explain why "Oh, boy" expresses pleasure or excitement.


How do I prevent my footer from taking up too much height?

I have a fairly standard page layout -- header, div with content and footer
         Header

Content
  Terms of Service   I would like the footer section to take up the remaining height on my HTML page so I applied these styles  html {     height: 100%; }  body {     margin: 0;     text-align: center;     height: 100%; }   footer {         background-color: #003162;         padding: 5px;         height: 100%;         font-family: Arial, Helvetica, sans-serif;         font-size: 80%; }  footer, footer a {         color: #fdb515; }   What is odd is that the footer is taking up too much space.  It is causing a scroll even though that's not what I requested --  .  How do I tell the footer to take up the remaining visible space?  I only want a scroll bar if the content isn't visible but its all there.


I have a navigation menu. When the user leaves the li I want the menu to wait for a short value of time before closing. Previously I made the code apply which worked fine until I wanted to give different delays. The issue is the event does not trigger.  I tried making a version of the item on jsfiddle which works fine -   My code:    $("#nextLeftNav li, #prevLeftNav li").on("mouseleave", function (event) {             var element = $(event.currentTarget);             element.removeClass("hover");             var delayMs = 600;             if($(this).is("#nextLeftNav li"))             {              delayMs = 3000;             }             timeOutMethod = setTimeout(timeoutNavbar, delayMs, element);      });  function timeoutNavbar(){     console.log("timeOutNavBar") }

     When I inspect prevLeftNav's only li I see the dimensions of around 200x20 and can physically see the li.


I have problem in some JavaScript that I am writing where the Switch statement does not seem to be working as expected.  switch (msg.ResultType) {   case 0:     $('#txtConsole').val("Some Val 0");     break;   case 1:     $('#txtConsole').val("Some Val 1");     break;   case 2:     $('#txtConsole').text("Some Val 2");     break; }   The ResultType is an integer value 0-2 and I can see that in FireBug.  In all cases, the switch transfers control to the final break statement which means all the logic is completely skipped.  What am I missing?


I have this text on a white bar in Illustrator, and I would like to make that part of the white bar transparent instead of what it currently is - the same color as the background.  I tried doing the clipping mask, but it does the opposite, it gets rid of the white bar and makes the text white  Can anyone offer any suggestions?    when I then try to make a compound path, the 2015 converts fine, but there is another compound path that I try to do this to and it does not work, and it also distorts some of the letters:


I am new to angularjs and I've been searching on the web the whole day just to find a solution in getting data from a local json file without having to use a localhost for my webapp. Unfortunately, I haven't found any. I tried using $http.get but I get Cross Origin * error.   Is there no other way that I could get the data from my local json file without having to locally host my webapp?  Does angularjs have any other function to get data from local json files without having to use its $http.get?


Non-zero eigenvalues of $AA^T$ and $A^TA$

As a part of an exercise I have to prove the following:  Let $A$ be an $(n \times m)$ matrix. Let $A^T$ be the transposed matrix of $A$. Then $AA^T$ is an $(n \times n)$ matrix and $A^TA$ is an $(m \times m)$ matrix. $AA^T$ then has a total of $n$ eigenvalues and $A^TA$ has a total of $m$ eigenvalues.  What I need to prove is the following:  $AA^T$ has an eigenvalue $\mu \not = 0$ $\Longleftrightarrow$ $A^TA$ has an eigenvalue $\mu \not = 0$  In other words, they have the same non-zero eigenvalues, and if one has more eigenvalues than the other, then these are all equal to $0$.  How can I prove this?  Thanks and regards.


GLMM using glmer() -- lack of convergence with a TEXTBOOK EXAMPLE

A supposedly simple, textbook example of a binary GLMM using adaptive Gauss-Hermite Quadrature with 5 fixed and 1 random effect is not converging. The example analysis that I'm trying to reproduce is from Hosmer et al (2013: 347).   The following code reproduces the problem:  install.packages("aplore3") require(aplore3) data("polypharm") polypharm$ID <- factor(polypharm$id) #Turn the Random Effect into a factor polypharm$inptmhv2 <- as.numeric(polypharm$inptmhv3 != "0") polypharm$race2 <- as.numeric(polypharm$race != "White") polypharm$gender_m <- as.numeric(polypharm$gender == "Male") require(lme4) mixed1 <-        glmer(polypharmacy ~ gender_m + age + mhv4 + race2 + inptmhv2 + (1|ID),       nAGQ = 2, # AFAIK this needs to be set to >1 or it's not GHQ         family = binomial,            data = polypharm)   And the result is  Warning message: In checkConv(attr(opt, "derivs"), opt$par, ctrl = control$checkConv,  :   Model failed to converge with max|grad| = 0.339924 (tol = 0.001, component 1)   In the help file, the author of glmer() says that up to 25 quadrature points may be used when there's only one random effect. I therefore tried refitting the model with every nAGP value from 1 through 25 (not shown), but none of those models converges either.   The model does converge when nAGP is set to 0 but, as I understand it, that method is essentially a cheap shortcut that sacrifices estimation accuracy -- and sure enough, the estimates thus obtained are quite different from those in Hosmer et al's example.  Since this dataset was specifically selected by eminent statisticians to serve as a didactic example of GLMMs, it seems hard to believe that convergence should be so hard to attain. The most plausible explanation is that I'm messing something up. But what?  I'm not opposed to using other packages either. But the chart on page 131 of  straightforwardly suggests that GHQ is the way to go, and glmer() seems the default choice for that.  References:  Hosmer, D. W., Lemeshow, S. & Sturdivant, R. X. (2013). Applied logistic regression (3rd ed.). Hoboken, N.J.: Wiley.


What kind of future verb tense is this: "will needs continue"?  These contests may take place at any time the competitors express their readiness, due notice of course, being given the day previous, for the benefit of the public. When once started, the gliding performances of a single contestant will needs continue several days, and plenty of entertainment is promised the public in this aero-department.  Source:  (see col. 6, the last paragraph.)


iCloud has space but iCloud Backup says that I don't have enough to complete a backup

I use 120 MB of iCloud storage space for iCloud Backup of my iPad & iPhone. There is still 4.8 GB free from 5 GB, but I have a notification in iPad's backup window that I'm lacking space to back up to iCloud and would rather not buy more space to back up today.


Using pgfplots with x-axis that is not evenly distributed

I am trying to plot a graph with the the following x-values:  0.01, 0.05, 0.1, 0.2, 0.3, 0.5, 0.6, 0.7, 0.8, and 0.9  When I set them to my xtick values, the numbers get pushed to the left, since they grow at different rates. I'm wondering if there's a way to have the values align to the x-axis properly.  This is how it looks, and my code follows:    \begin{tikzpicture}  \begin{axis}[     title={Throughput vs. Arrival Rate (N = 10)},     xlabel={$\lambda$ (Arrival Rate)},     ylabel={Throughput},     xmin=0.01, xmax=0.9,     ymin=0, ymax=10,     xtick={0.01,0.05,0.1,0.2,0.3,0.5,0.6,0.7,0.8,0.9},     ytick={0,1,2,3,4,5,6,7,8,9,10},     legend pos=north west,     ymajorgrids=true,     grid style=dashed, ]  % Simulated \addplot[     color=blue,     mark=square,     line width = 1.2pt,     ]     coordinates {     (0.01,0.111)(0.05,0.0833)(0.1,0.267)(0.2,0.672)(0.3,1.027)(0.5, 3.2)(0.6, 8.1)(0.7,3.2)(0.8, 0)(0.9,0)     };   \end{axis} \end{tikzpicture}


Comparing proof of $R[[x]]^*$ consists of $\sum_{n \geq 0}a_{n}x^n (a_{n} \in R) ,a_{0} \in R^* ,R$ an integral domain to $R$ a ring.

I want to answer letter $(b)$ in this question: Let $R$ be an integral domain and let $R[[x]]$ be the corresponding ring of formal power series. $(a)$ Show that $R[[x]]$ is an integral domain. $(b)$Show that $R[[x]]^*$ consists of the series $\sum_{n \geq 0}a_{n}x^n (a_{n} \in R)$ such that $a_{0} \in R^*.$ My question is: I found a solution here  in case of $R$ a ring, I am wondering how will my solution differ as my $R$ is an integral domain?


I cannot access my Windows drive from a Ubuntu live session because the "disk contains an unclean file system". How do I mount it anyways?  There's only one document I (desperately) need to get from the drive before I can reinstall the OS. Windows won't let me boot because apparently files got corrupted (no idea how, the PC just shut down while I wasn't using it with a download running) and I can't repair the damage with the install media as suggested by below picture taken after trying to boot into Windows. The recovery tool tells me it's beyond repair.  I'm not sure if the damage is because of a virus or a faulty SSD. I think it's the latter.  Right now I'm in the process of creating an image of the whole disk (will post logfile):  ubuntu@ubuntu:/media/ubuntu/TOSHIBA EXT$ sudo ddrescue -d /dev/sda test.img test.logfile     Translation from German (rough): "Recovery. PC/device has to be repaired. An app or OS couldn't be loaded because a required file is missing or contains errors. You have to use recovery tools."    Sda4 is the data partition on the SSD. The one I need access to.  Dmesg (with info on failed mount attempt at the end):   sudo ntfsfix -d /dev/sda   came up with this  Mounting volume... NTFS signature is missing. FAILED Attempting to correct errors... NTFS signature is missing. FAILED Failed to startup volume: Invalid argument NTFS signature is missing. Trying the alternate boot sector Unrecoverable error Volume is corrupt. You should run chkdsk.   I think I made the mistake to not specify a partition. When I instead use "sda4" (the correct partition) I get this  Mounting volume... ntfs_attr_pread_i: ntfs_pread failed: Input/output error Failed to read of MFT, mft=160412 count=1 br=-1: Input/output error Inode is corrupt (43352): Input/output error FAILED Attempting to correct errors...  Processing $MFT and $MFTMirr... Reading $MFT... OK Reading $MFTMirr... OK Comparing $MFTMirr to $MFT... OK Processing of $MFT and $MFTMirr completed successfully. Setting required flags on partition... OK Going to empty the journal ($LogFile)... OK ntfs_attr_pread_i: ntfs_pread failed: Input/output error Failed to read of MFT, mft=160412 count=1 br=-1: Input/output error Inode is corrupt (43352): Input/output error Remount failed: Input/output error   When I tried  sudo mount -t ntfs-3g -o ro,recover /dev/sda4 /mnt   it gave me  ntfs_attr_pread_i: ntfs_pread failed: Input/output error Failed to read NTFS $Bitmap: Input/output error NTFS is either inconsistent, or there is a hardware fault, or it's a SoftRAID/FakeRAID hardware. In the first case run chkdsk /f on Windows then reboot into Windows twice. The usage of the /f parameter is very important! If the device is a SoftRAID/FakeRAID then first activate it and mount a different device under the /dev/mapper/ directory, (e.g. /dev/mapper/nvidia_eahaabcc1). Please see the 'dmraid' documentation for more details.   I'm beginning to get worried now. I really need this one file. It's a paper I've been working on for quite some time. Could it be my SSD gave up the ghost?


PHP - Why floor() give me another result of sams calculation


Is it ok to omit a possessive apostrophe before a capitalized appellation (President, country name, VP, PM)?

In a recent Financial Times article (Yemen PM Escapes Assissnation), the apostrophe necessary to show possession was left out. I've seen colleagues do it as well. Isn't it supposed to be "Yemen's PM Escapes...?" Other times I've seen people write "Japan Minister of Finance tackles deflation..." or "India VP resigns..." I have noticed that in most of these cases, the omission of the apostrophe was right before a captilazed appellation (president, country, municipal, etc.) What's going on? Firm grammar rules stipulate that there be an apostrophe, yet there isn't one. If the FT does it, then there must be an exception (in journalism?) that I'm unaware of. Must there or must there not be an apostrophe?


How to interpret output from Linux 'top' command?

Following a discussion made  about how PHP-FPM consuming memory, I just found a problem in reading the memory in top command. Here is a screenshot of my top just after restarting PHP-FPM. Everything is normal: about 20 PHP-FPM processes, each consuming 5.5MB memory (0.3% of total).    Here is the aged server right before restart of PHP-FPM (one day after the previous restart). Here, we still have about 25 PHP-FPM with double memory usage (10MB indicating 0.5% of total). Thus, the total memory used should be 600-700 MB. Then, why 1.6GB memory has been used?


There is a lack of clarity in where to use Blender menu, panel or the operator. I am familiar with inheritance in Qt where QDialog, QWidget, QMessageBox, QMainWindow are used as required. As a matter of fact ncurses library and wx also has similar inheritance pattern.  I know there is no relation between Blender and Qt, or wx or ncurses but I was trying to learn from the Blender Python documents and information is very sparse. Is there any secret manual available somewhere? Also I'm not keeping any other library as a template to compare against Blender types, I'm just new to the whole of Blender.


Computing the coefficient in a large polynomial

What is the coefficient of $x^{10}$ in the expansion of $(5 x^2 + 3)^{14}$?   (I would prefer to know the answer as a mathematical expression rather than a number.)  May I know how to approach this question and what will be the answer? Thanks


Which of the following polynomials are subspaces of $\mathbb{P}_n$ for an appropriate value of n?

Definition. A subspace  of a vector space V is a subset H of V that has three properties  (a) The zero vector of V is in H.  (b) $\forall$ u, v $\in H$, we have  u + v $\in H$.   (c) $\forall$ u $\in H$, c scalar, we have c  u $\in H$.  For $n \geq$ 0, denote $\mathbb{P}_n$ to be the set of all polynomials of degree at most $n$.  Which of the following are subspaces of $\mathbb{P}_n$ for an appropriate value of $n$? Support your answer with reason.  (a) All polynomials of the form $p(t) = a + t^2$, where $a \in \mathbb{R}$.  (b) All polynomials of degree at most 3, with integers as coefficients.  Solution:  Both the statements (a) and (b) above are not subspaces of $\mathbb{P}_n$.  Reason:  For part (a), All polynomials of the form $p(t) = a + t^2$, where $a \in \mathbb{R}$, is not a subspace because it failed to meet the standards of the first property stated above, that is, the coefficient of the $t^2$ term is always a 1, therefore the zero vector is not in this subspace of polynomials.    For part (b), All polynomials of degree at most 3, with integers as coefficents is also not a subspace becuase it as well failed to meet the standards of the third property, that is, integer coefficents, when multiplied by a real scalar, will not necessarily be of integer type leading to integer coefficents. Thusly, the resulting polynomial will not be in the subset of polynomials $\mathbb{P}_n$. $\Box$  Can someone please look at this and see if I have the right idea and approach to this question. Thank You


Sign of Lagrangian and stress-energy tensor for relativistic dust

I enjoy the derivation of $T_{\mu\nu} = \rho u_\mu u_\nu$ by Dirac, reproduced in . But when I try to rewrite it with metric convention $(-+++)$ (used by MTW), I find a rather puzzling result.   The action for the relativistic dust should now be: $$ S_M = -\int \rho c \sqrt{-v_\mu v^\mu} \sqrt{ |\det g| } d^4 x         = -\int c \sqrt{-p_\mu p^\mu} d^4 x $$ since $v_\mu v^\mu < 0,\, p_\mu p^\mu < 0$, while the rest of the derivation remains almost the same, which is: $$     \delta S_M         = - \delta \int c \sqrt{-{p}_\mu {p}^\mu} d^4 x = $$ $$         = - \int c {\delta(-g^{\mu\nu} {p}_\mu {p}_\nu)             \over 2\sqrt{-{p}_\alpha {p}^\alpha}} d^4 x = $$ $$         = \int c { {p}_\mu {p}_\nu             \over 2\sqrt{-{p}_\alpha {p}^\alpha}}             \delta(g^{\mu\nu}) d^4 x = $$ $$         = \int c { \rho v_\mu \rho v_\nu             \sqrt{ |\det g| }^2             \over 2 \rho c \sqrt{ |\det g| } }              \delta(g^{\mu\nu}) d^4 x = $$ $$         = \int {1\over2} \rho v_\mu v_\nu              \delta(g^{\mu\nu}) \sqrt{ |\det g| } d^4 x $$ From which we calculate the stress energy tensor using the standard GR formula for it: $$     T_{\mu\nu}         = - {2\over\sqrt{ |\det g| }}{\delta S_M\over\delta g^{\mu\nu}} = $$ $$         = - {2\over\sqrt{ |\det g| }} \left(                 {1\over2} \rho v_\mu v_\nu \sqrt{ |\det g| }             \right)= $$ $$         = - \rho v_\mu v_\nu $$ As you can see, it gives an extra minus sign. Clearly I've done something stupid, but I just couldn't spot it. Please help me find that mistake (or mistakes) in the above derivation.


How to reduce a large internal view state / what is in the internal view state?

I'm building an account search page that lets users select accounts and then pass them to other pages to perform various actions on them.  Unfortunately users are reporting hitting the view state limit.  Which leads me to a broader question: what is in in the internal view state and how can I reduce it?  I've already made everything transient I can, and when I look at the view state inspector my controller only uses a modest 15kb, but the "Internal" component of the view state is upwards of 90kb.  Does anyone have any tips for how to reduce the "Internal" component of the view state?  Some additional details.  The page is not using any components. The page has only one form on it.  The controller does reference a couple other classes.  The controller does not store any state that can be regenerated in code on the postback.  EDIT: Uploaded a  with a thoroughly edited version of the code.  The code will likely not compile initially but should give some idea of the design.  EDIT2: Here's a screenshot of what the page looks like from a related post on the    EDIT3: Here's a screenshot with a large result set loaded.  If I group these results I'll exceed the view state limit.  Result set size is 500 records and 1 grouping when the limit is reached.


I have an iPad 1 with iOS 5.1.1 that won't download any apps or update its OS. It was donated to my school so it was totally wiped before we got it.  I've tried the work around previously mentioned of downloading the apps in iTunes then dragging them over to my device that is also connected to iTunes. When I do this, a dialogue box comes up saying it was unable to install the app because the app requires a newer version of iOS. I'm really hoping Apple didn't make it so a perfectly good piece of tech is obsolete by not making iOS upgrades or apps compatible with their older technology.


Windows 8 opens 'moviemaker' when trying to access hyperterminal program

How can I have my Windows 8 system recognize the .ht file extension to launch a hyper terminal app?  I am using an HP Envy tablet.


Why the force is inversly proportional to the square of distance?

Lesser the distance higher the force of attraction.but why it is the square of distance?And also the reason i guess for this force is the attraction force between atoms ( electrons of one atom and proton of the other) . But when the distance become  lesser and lesser,the repulsive force will overcome the attractive force isnt it?Then wont the attractive force decrease?


What are 10bit displays worth with all sources being saved in 8bit format

From what I know all images you can create with RGB are 24 bit (8 bit per channel).  There are new 10 bit monitors coming into daylight these days. What is their advantage over 8 bit, if all (or almost all) sources are 24bit not 30 bit.  Even Photoshop has 10bit support... but you still can describe one channel with 0-255 (8bit) not 0-1023 (10bit)


continuous function: preimage of closure of a set is closure of preimage

i am struggeling with the following problem: let $f:X\to Y$ be a continuous mapping bet ween two metric spaces.   Does it hold that $f^{-1}(\overline{A})=\overline{f^{-1}(A)}$ and $f^{-1}(int(A))=int(f^{-1}(A))$, where the overline denotes the closure of a set and $int()$ the interior of a set.  One direction is obvious: $f^{-1}(A)\subset f^{-1}(\overline{A})$ and by continuity of $f$ the set$f^{-1}(\overline{A})$ is closed. So we proved $\overline{f^{-1}(A)}\subset f^{-1}(\overline{A}$. Any idea or reference where I can find the proof or an counter example?


Google Sheets IMPORTHTML error "could not fetch url"

The following in Google a sheet =IMPORTHTML("http://finance.yahoo.com/quote/INTC", "table", 2)  results in #N/A with an error message could not fetch url. However, the following works fine. =IMPORTHTML("http://en.wikipedia.org/wiki/Demographics_of_India","table",4)  Could anyone point out my mistakes about the yahoo finance?


Distinct integer solutions to $a^2+b^2=c^2+d^2$

I'm trying to find integer solutions to $$a^2+b^2=c^2+d^2$$  with values  $a> c > d > b>0$  Or in other words, two triangles with integer legs and equal hypotenuse lengths, not necessarily integer. Seems like a Diophantine equation to me, but I only learned how to solve Diophantine equations in the form of Pell's equations. I couldn't find anything on this equation when I checked Wikipedia. It is similar to a Pythagorean quadruple, although not quite, so that's not helpful either. How do I find integer solutions to this?


Physical reason of difference between normal force in a banked curve and an inclined plane.

When determining the centripetal force on an object on a banked curve, it is stated that the banking angle for a given speed and radius is found by :  tanθ = v^2/rg   It is found as follows:  The normal force on the object is resolved into components. The x-component (the one providing the centripetal force) is:   N*sinθ = mv^2/r   Then, the y component is set equal to mg:  N*cosθ = mg =>N = mg/cosθ  Dividing Nsinθ by Ncosθ, we get  :   tanθ = v^2/rg  I'm fine with that.   Here is where I'm confused. When resolving the forces of an object resting on an inclined plane: The component down and parallel to the plane due to gravity is:   mg*sinθ.  The component representing the force of gravity into (perpendicular) to the plane is:  mg*cosθ.   The normal force is equal to this component into the plane by Newton's 3rd Law, so,  N =mg*cosθ.    Why in the first scenario (banked curve) is   N=mg/cosθ,   HOWEVER, in the second (inclined plane)   N=mg*cosθ ?  How can this be? There are two different values for N?  Is the normal force in the first scenario (banked curve) greater than mgcosθ because:   a) the normal force also is responsible for the centripetal acceleration, so it needs to be greater?   Or,   b) the car is not sliding down the curve, so the normal force is greater because of the translational equilibrium requirement? The textbook that I have (Resnick, Fundamentals of Physics) seems to suggest (b), since they use the equation for equilibrium in the Y direction. But if that is the case, then what is PHYSICALLY CREATING this "extra" normal force as compared to the second scenario (inclined plane)?


I have met a question when using cd command in a script. here is the test below, so, could anyone help to tell the reason?  why does not "/bin/sh  cd /root/eos/" work ,but "/bin/sh -c ls &&  cd /root/eos/" works well in centos thanks.   [root@izbp16eo65uiwii1mfm63tz eos]# pwd /root/testeosnode/CryptoKylin-Testnet/docker/eos [root@izbp16eo65uiwii1mfm63tz eos]# /bin/sh  cd /root/eos/ [root@izbp16eo65uiwii1mfm63tz eos]# pwd /root/testeosnode/CryptoKylin-Testnet/docker/eos [root@izbp16eo65uiwii1mfm63tz eos]# /bin/sh -c ls &&  cd /root/eos/ build.log  build.sh  Dockerfile  eos [root@izbp16eo65uiwii1mfm63tz eos]# pwd /root/eos    env CentOS Linux release 7.5.1804 (Core) [root@izbp16eo65uiwii1mfm63tz eos]# ls -l /bin/sh lrwxrwxrwx 1 root root 4 10oct  9 18:00 /bin/sh -> bash


Prove that for all positive integers $n........$

Prove that for all positive integers $n, 1^3+2^3+\ldots+n^3=(1+2+\ldots+n)^2$


Given a prime $p$ and a natural number $k$, such that $k$ is not divisible by $p - 1$, prove that $\sum_{i = 1}^{p - 1}i^k \equiv 0 \pmod p$.  I split the proof into two cases: one where $k$ is odd and another where it is even.  The case where $k$ is odd can be proven as follows:  $$\sum_{i = 1}^{p - 1}i^k \equiv \sum_{i = 1}^{\frac{p - 1}{2}}i^k + \sum_{i = 1}^{\frac{p - 1}{2}}(-i)^k \pmod p$$  Since $k$ is odd each $(-i)^k = -i^k$, and will cancel with the positive $i$ leaving a zero. Therefore,   $$\sum_{i = 1}^{p - 1}i^k \equiv 0 \pmod p \text{ if $k$ is odd.} $$   I approached the case where $k$ is even in a similar fashion.   $$\sum_{i = 1}^{p - 1}i^k \equiv \sum_{i = 1}^{\frac{p - 1}{2}}i^k + \sum_{i = 1}^{\frac{p - 1}{2}}(-i)^k \equiv 2(\sum_{i = 1}^{\frac{p - 1}{2}}i^k) \space \pmod p$$  Since $p$ is prime, we just need to prove that $\displaystyle\sum_{i = 1}^{\frac{p - 1}{2}}i^k \equiv 0 \pmod p$.  I was stumped after this, so I considered a counterexample, one where $k$ is divisible by $p - 1$. In that I considered a case where $p = 5, k = 8$:  $$1^8 + 2^8 + 3^8 + 4^8 \equiv 1 + 1 + 1 + 1 \space \pmod p$$  This and a few other cases led to the conjecture that all the numbers below $p$ have a mod cycle $(mod \space p)$ that is divisible by $p - 1$. I tested it with $p = 7$.  $2: 2, 4, {\color{red}1}$  $3: 3, 2, 6, 4, 5, {\color{red}1}$  $4: 4, 2, {\color{red}1}$  $5: 5, 4, 6, 2, 3, {\color{red}1}$    After this I was stuck. I couldn't see how this would help me solve the problem. And, more importantly, I couldn't prove my conjecture.


I have tried many names for Pokemon Go but they say it's not available

I need a nick name for Pokemon Go to continue the game. I tried more than 100 names . Can you please send me a available name.


Why wasn't gunpowder more common in Middle Earth?

By the Third Age, gunpowder was obviously invented, but it was very rarely used. In late medieval and early modern Europe (and subsequently on the whole planet) it completely changed warfare.  As Middle Earth is a very low-magic setting, gunpowder would not be made obsolete by magic, as magic hardly exists at all.   We don't see any cannon artillery, or tercios which would mop up the floor with a similarly sized army from Middle Earth (maybe except the Elves whose archery would probably still be superior to muskets).


Is 'if I would have ..., I would have ...' a valid conditional?

Today, I read a tweet where the used conditional structure did not fit any of the conditional types taught in the language books I've read.     if I would have relied on the Fake News of CNN, NBC, ABC, CBS, washpost or nytimes, I would have had ZERO chance winning WH [sic]   Basically, if I understand it well, it's structured as:     if (subject) would have (past participle) ..., (subject) would have (past participle)... .   I tried to search for conditional types and most sites listed Zero, Type 1, 2, 3 and mixed conditionals, but unfortunately, I didn't find any that resembles the quoted tweet.  Is 'if I would have ..., I would have ...' a valid/correct conditional?  If it is not, how bad it sounds to a native English speaker? How frequently is it used incorrectly?


Say I have the following files:   |-- bar `-- foo     |-- type_A_1     |-- type_A_2     |-- type_B_1     |-- type_B_2     |-- type_B_xx     |-- type_B_xx     `-- something_else    I thought the following command  print -l foo/*~{type_B*}   would print everything under foo except things that start with type_B but it doesn't, instead it prints everything under foo:  foo/type_A_1 foo/type_A_2 foo/type_B_1 foo/type_B_2 foo/type_B_xx foo/something_else   I also tried print -l foo/*~type_B and got the same thing.  How does the exception wildcard ~ work in zsh?


Compute $\lim_{n \rightarrow \infty} n^{\frac{1}{n}}$

Compute $\displaystyle\lim_{n\rightarrow\infty} n^{\frac{1}{n}}$  If there exists the sequence $x_n = n^{\frac{1}{n}} - 1$ and we have established the fact: $x_{n}^2 \leq \frac{2}{n}$. Compute $\displaystyle\lim_{n\rightarrow\infty}n^{\frac{1}{n}}$  Truly frustrated at this point because I know it is just a small step in my observations that will allow me to draw the final conclusion and not accomplishing it has me very upset. What am I not seeing that would help me along the path ?


Are multiple SE sites covering the same subject, with higher specificity, detrimental?

I found it hard to condense my question into a simple title and not sure it fully explains my question.  I am not sure if this occurs elsewhere on SE, but I have a specific example:  SuperUser covers general computer use, including Unix, Linux, and Ubuntu.  Unix & Linux covers Unix, Linux, and Ubuntu.  Ask Ubuntu covers Ubuntu.  Logically, would think that if you have a question specific to Ubuntu, you should ask on Ask Ubuntu and you will get the fastest, best answer, with Unix & Linux being next, and SuperUser being last.  However, the reality is the exact opposite.  A question on Ubuntu on Ask Ubuntu can go for large lengths of time, with little views and few to no answers.  The same question on SuperUse  will receive multiple answers, extremely quickly.  I am not belittling the users of the other, more specific sites in any way.  However, its simply a function of the number of users.  More people simply means more answers, faster.  When it comes to users, SuperUser is a behemoth.  I have personally experienced this, as well as others I have talked to.  I have told those people to remove their question from the other sites and post on SuperUser, because of this.  They have told me that this solved their problems.  It definitely appears to me that is detrimental to SE.  A new user coming in asking a question on Ask Ubuntu will get frustrated from the lack of answers and potentially write off SE as a resource.  They dont realize that they thought they were choosing the best forum to ask their question, they were in fact choosing the worst.  Am I wrong?  If not, can this be fixed?  Should this be fixed?


How to *disable* automatic reboots in Windows 10 Home (January 2017)

I wish to prevent windows from rebooting after doing an update because sometimes I want to leave my PC performing a task unattended for days on end.   Now before you rush to tell me this is a duplicate of , I should point out that A) Most of the (very long) most upvoted answer is devoted to more premium versions of Windows which includes gpedit which Home does not have. B) There are a lot of comments about solutions not working and this may well be date dependant, i.e. some solutions perhaps used to work but don't any more. I think this issue is so important that this question needs to be asked again so that the up/down votes will correspond to the current state of play.  I would also like to add an additional part of the question which is - once I have made the changes necessary to prevent forced reboots, is there some way of telling that I have done it correctly? I.e. some place in windows where it will actually tell me that future reboots have been disabled.  By the way I am asking this question now because I did attempt to follow the prevent-reboot solutions from a variety of sources but my PC rebooted itself last night (12 Jan 2017).  ANSWER FOUND: This is a simple solution that works: .


While passing an object reference to a method in java members are updating but reference remains the same. Why?

info.name and info.phone are changing after passing to defaultEntry(Info infoObject) but reference not changing to null why? can anybody please explain this scenario as well as working of java methods. Is there any difference between c functions and java methods working mechanism? Thanks in advance :)         class Info {         String name = "Sagar Pudi";         String phone = "9999999999";     }      public class MemberDetails {         public void defaultEntry(Info infoObject) {             infoObject.name = "DEFAULT_MEMBER";             infoObject.phone = "NO_PHONE";             infoObject = null;         }          public static void main(String[] args) {              Info info = new Info();             System.out.println("Before : " + info.name + "<->" + info.phone);              MemberDetails md = new MemberDetails();             md.defaultEntry(info);             System.out.println("After  : " + info.name + "<->" + info.phone);             if (info != null)             System.out.println("info  is still an object of " + info.getClass());         }     }   Output:  Before : Sagar Pudi<->9999999999 After  : DEFAULT_MEMBER<->NO_PHONE info  is still an object of class Info


Should we automatically protect questions that are at least a certain age?

I came across a question on serverfault today that is about 18 months old.  The reason I found it is that a 1 rep user had just added an answer.  I didn't notice the date at first, and added my own answer as well.  This isn't a huge deal for one question, but what about the general case?  Does it make sense that any question over, say, a year (or even just six months) should be automatically protected? I know technology changes and we want the ability to keep older questions up to date, but remember that protecting a question only locks it for users with a small rep. What about including views as part of the equation?  A question that earns a "Popular Question" badge is probably getting enough views from low rep users to really need protection and enough views from higher rep users to get the edit and new answer attention when needed, but lower view questions maybe either don't need the protection or do need the edit/answer help from anyone who does happen to land at the question. Update: For context, here is a link to a query that shows actual answers that would have been blocked under this proposal, so we can judge the typical quality.  Note that to accurately judge this you have to view them in the context of answers that are already available to the question at the time the answer is added:  And here is a query to show how many questions would be effected:  Notethat this is a naive query: it only checks answer count rather than whether the answer has an upvote, and there's no way right now to know how many of these are already protected.  Using the current data set, the result is 114039, or a little less than 1/10th of all questions, and because of the other limitations it's probably even smaller.


Every six months I used to delete the mails in my inbox but now I need access to one of the emails I deleted a year back.  Is there any way to recover the mail?


Can a limit of an integral be moved inside the integral?

After coming across this question: , I have the following question:     When taking the limit of an integral, is it valid to move the limit inside the integral, providing the limit does not affect the limits of integration?   For instance in the question, the OP is trying to determine that:  $$\lim_{n\to\infty}\int_{0}^{1}{\frac{dx}{(1+\frac{x}{n})^{n}}}=1-\rm{e}^{-1}$$  The answers to the question involve evaluating the integral and then taking the limit to prove the result; but I was wondering if it would be valid to move the integral inside the limit, that is:  $$\lim_{n\to\infty}{\int_{0}^{1}{\frac{dx}{(1+\frac{x}{n})^{n}}}}=\int_{0}^{1}{\lim_{n\to\infty}\frac{dx}{(1+\frac{x}{n})^{n}}}=\int_{0}^{1}{\frac{dx}{\rm{e}^{x}}}=\rm{e}^{0}-\rm{e}^{-1}=1-\rm{e}^{-1}$$  As required. So is this a valid technique, or is it just coincidental that this works?


My friend suggested nuking the following limit using Taylor, but I am convinced there is a 'nicer' method to solving it. $$\lim_{x\to\infty}x^{\frac23}\left((x+1)^\frac13-x^\frac13\right)=?$$ Multiplying it through to obtain the expression $(x^3+x^2)^\frac13-x$ hasn't helped, and neither has multiplying with the conjugate to obtain the expression $\frac{x^\frac23\left((x+1)^\frac23-x^\frac23\right)}{(x+1)^\frac13+x^\frac13}$. Is there are neat algebraic manipulation that can be performed to evaluate this limit? Thanks!


How can I scan for possible viruses on my Ubuntu system?

I think I may have a virus. How would I go about checking for a virus and how can I protect my computer from any other virus? Please give detailed answer as I'm still learning about Ubuntu.


Show that $\int_{-\infty}^{+\infty} e^{-(\frac{a}{x^2}+x^2 )}dx=\sqrt{\pi}e^{-2\sqrt{a} }, \forall a>0$. I know this can be formulated in terms of conditional characteristic function of Cauchy distribution. But that's why I'm here to ask how this integral is computed in the first place (possibly using some complex analysis tools? I'm interested to know!). I tried the standard trick: $$\begin{aligned}\left(\int_{-\infty}^{+\infty} e^{-(\frac{a}{x^2}+x^2 )}dx\right)^2=&\int_{-\infty}^{+\infty}\int_{-\infty}^{+\infty} e^{-\left(\frac{a}{x^2}+\frac{a}{y^2}+x^2+y^2  \right)}dxdy\\=&\int_{-\infty}^{+\infty}\int_{-\infty}^{+\infty} e^{-\left(\frac{a(x^2+y^2)}{x^2y^2}+x^2+y^2  \right)}dxdy\\=&\int_{0}^{2\pi}\int_{0}^{+\infty} e^{-\left(\frac{4a}{\sin^2(2\theta)}+r^2  \right)} rdr d\theta \\=&\int_{0}^{+\infty} e^{-r^2} rdr \int_{0}^{2\pi} e^{-\frac{4a}{ (\sin^2(2\theta))}  }d\theta\\=&\int_{0}^{\pi} e^{-\frac{4a}{ (\sin^2(\theta))}  }d\theta \end{aligned}$$ How should I continue from here?


Moving one vertex moves all connected vertices

Sometimes when I try to move a vertice it moves the triangles around it to. But it won't do it with a certain mesh. How do I make it so when I move the point it moves all the triangles connected to it?  notice how in the first picture I lift it and only one part comes up  but in the second picture all the shapes around it lift up too. that's what I want to happen


I have a device on which I would like to install Ubuntu. How do I find out if Ubuntu will work on it?


What do I use on linux to make a python program executable

I just installed a linux system (Kubuntu) and was wondering if there is a program to make python programs executable for linux.


I was updating my ubuntu 12.04 and got few issues. I think something is broken that has to be fixed. Kindly help me to fix the issue when i run update command. I am receiving below errors.  W: There is no public key available for the following key IDs: 1397BC53640DB551  W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/Release  Unable to find expected entry 'main/binary-i386/Packages' in Release file (Wrong sources.list entry or malformed file)  W: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/precise/restricted/source/Sources  Hash Sum mismatch  E: Some index files failed to download. They have been ignored, or old ones used instead.


In Convolutional networks, how to do input data normalization? is it necessary?

I'm wondering about data normalization in CNN, how can we do it for the input images?, what can it add to the model's performance? and what are the main pre-processing techniques before doing the convolutional layer?  Happy to get extra-reading, thanks.  UPDATE:  I'm looking for how to practically normalize the data inputs, I didn't get it!  . Additional reading (explanation, papers) will be so helpful.


A question regarding Hatcher's exercise problem

I'm studying Hatcher's algebraic topology, and stuck at a question.  Here what I understand is that the question requires me to describe RP^n as a quotient of a delta complex and S^n.  Is my understanding correct? If so, could anyone help me how to do so? I'm having difficulties becuase RP^n or S^n can't be visualized in high dimensions