I've been working on a bunch of layers of differing co-ordinates projections within a single dataframe.  Because I haven't really got my head around this, and because its all been working just fine, I didn't want to touch it.  However, one of the functions I was trying to perform wouldn't work (extract multi values to points) and I suspected this was because of coordinate conflicts.    My data frame properties show that I have layers with the following coordinates in it:     GCS_WGS_1984 NZGD_2000_New_Zealand_Transverse_Mercator NZGD_2000_Transvers_Mercator  NZTM   I guess they should all be on the same.    I have just tried to change the projection of 3 layers (why didn't I check after the first one???) from GCS_WGS_1984 to NZGD_2000_New_Zealand_Transverse_mercator using "Define projection tool".  They've gone missing, even zooming to layer wont find it.    The properties of the missing layers show the extent in lat/long.  The properties of the layers I can see (haven't changed the projections of) show the extent in meters.  I'm wondering if this could be the issue, and if it is how to change it.  If its not this, what could it be? Whats the best way forward?    I have re projected (as per advice) and can now see my layers on the same page - but they still don't overlap.  I suspect this is because of extents.  The attached images will show where the layers of extent type A and B respectively are showing.  Projecting has not changed this... is there a way to change it?  Maybe try another co-ordinate system?      ]


Chrome - how do I actually VIEW a https certificate?

While Chrome is happy to show me certificates when they are invalid, with a nice warning message, I've just tried to view a certificate for a valid site and found there's no obvious way to do so.  If you click the 'Secure' button in the url bar it shows you the current options for all the various access a site can request, and tells you the communications is secured with https and a link to a google page explaining what this is, but doesn't actually show you any details about the site!  How do you view the cert manually, within Chrome?


With commands like top and the gui based System Monitor I can see that at the moment I have several zombie processes.  What are zombie processes?  Do they affect the performance of the system or the application they are zombie to. Do they use too much memory or any memory at all?


How to ensure an event is only subscribed to once

I would like to ensure that I only subscribe once in a particular class for an event on an instance.  For example I would like to be able to do the following:  if (*not already subscribed*) {     member.Event += new MemeberClass.Delegate(handler); }   How would I go about implementing such a guard?


Just installed Ubuntu 14.04.1 on a Dell 755.     Trying to install the above adapter. lsusb lists it as;  Bus 001 Device 004: ID 148f:760b Ralink Technology, Corp.   Any instructions I have found to get this chipset (MT7601UM) do not work.   Any help on this would be greatly appreciated! I bought 8 of these and they work great on Win 7. Just can't get it to run on Ubuntu or Zorin.


Can someone show me how to get the top & left position of a div or span element when one is not specified? ie: stuff stuff  In the above, if I do: document.getElementById('11a').style.top  The value of 55px is returned. However, if I try that for span '12a', then nothing gets returned. I have a bunch of div/spans on a page that I cannot specify the top/left properties for, but I need to display a div directly under that element.


2D animated sprite jumping and gravity physics

I'm currently writing a Megaman clone for my school project. So far all I did was making the character run and stay put when needed. Know I want to be able to make him jump using the 'X' button. I already have the animation sheet of the jump. But I really can't figure out how to do it and how the physics work after reading so much about it both here and other places. I think you get what I mean. From the state of staying put or running, going to a jumping position and landing. Also to be able to press left/right and the jump button to jump in the direction(I know It's stupid that I explain all of this because you probably know all this but just in case). Anyway this is my code for Game1:  And this is the code for my Animated Sprites class:  I'm not saying it's the smartest writing, but it's only a school project so I need it to work so I'm fine with it. Thanks a lot, a lot in advance for those who read this and are going to help.


How to deduct the coefficient of the Dirichlet distribution?

I am studying the textbook Introduction to Probability Models by Sheldon Ross. In Section 3.6 page 151 (10th edition), the author uses the Dirichlet distribution to deduct the coefficient of a "uniform" distribution. The "uniform" distribution is   $$f(p_1,p_2,\cdots,p_m) = \left\{\begin{array}{rl} c, & 0\leq p_i \leq 1, i = 1,\cdots, m, \sum_1^mp_i=1 \\ 0, & \text{otherwise} \end{array} \right.$$  So I check the wikipedia page about Dirichlet distribution. Among all the material I find out that "uniform" distribution (with constraint on the sum of variables) follows a symmetric Dirichlet distribution with $\alpha$'s become identical. $$f(x_1,\dots, x_{K-1}; \alpha) = \frac{\Gamma(\alpha K)}{\Gamma(\alpha)^K} \prod_{i=1}^K x_i^{\alpha - 1}$$ Thus it gives me the result as the author indicate $c=(m-1)!$.   The question is, to me, how to get the coefficient without referring to the Dirichlet distribution or get the coefficient given the kernel of the Dirichlet distribution, of course with the constraint that $\sum x_i = 1$.   I find out a post in the same site, which is to . Part of the solution can answer this question. However, it maybe of some value to help others search on this topic, so I decide not to remove the post.   Since that version is a little bit hard to understand, Can you give a more plain explanation?


Copying different files from different folders

I have 400 folders (/123_0/, /123_1/, ...) and inside each one I have a file with extension *.root and different names. I just want to copy these files to a destination /destination/. How can I do it?


Upgrading LTS to LTS (server) -- why wait for the first point release?

Does anyone know the (specific) reasons that it is recommended that old LTS server users wait until the point release to upgrade?  Is it just a matter of bug fixes and waiting for improved stability for production servers, or is there something more fundamental than that?


Regular Expressions: Is there an AND operator?

Obviously, you can use the | (pipe?) to represent OR, but is there a way to represent AND as well?  Specifically, I'd like to match paragraphs of text that contain ALL of a certain phrase, but in no particular order.


How can I start qBittorrent on system boot?

So I've got a bit of an issue trying to get qBittorrent to start on boot. I'm running 16.04.  I've tried to start it by using a crontab @reboot, but this unfortunately didn't work. Any ideas on how to get this to work?


I want to plot this graph, but I don't know how to code the words in the nodes.     Here is my code:  \documentclass{article} \usepackage{amsmath} \usepackage{titletoc} \usepackage{tikz} \usetikzlibrary{trees,positioning,fit}  \begin{document}{\allowdisplaybreaks[4]}  \tikzstyle{bag} = [text width=2em, text centered] \tikzstyle{end} = []  \begin{center} \begin{tikzpicture}[sloped] \node (a) at ( 0,0) [bag] {$\ln r_0$}; \node (b1) at ( 3,1.5) [bag] {$\ln r_{10} + \sigma_1\sqrt{\Delta t_1}$}; \node (b2) at ( 3,-1.5) [bag] {$\ln r_{10}$}; \node (c1) at ( 6,3) [bag] {$\ln r_{20} + 2\sigma_2\sqrt{\Delta t_2}$}; \node (c2) at ( 6,1.5) [bag] {$\textrm{Mean} = \ln r_{20} + \dfrac{3}{2}\sigma_2\sqrt{\Delta t_2}$\\$\textrm{Mean Change} = \mu_{11}\Delta t_2 = \ln\dfrac{r_{20}}{r_{10}} + \dfrac{3}{2}\sigma_2\sqrt{\Delta t_2} - \sigma_1\sqrt{\Delta t_1}$}; \node (c3) at ( 6,0) [bag] {$\ln r_{20} + \sigma_2\sqrt{\Delta t_2}$}; \node (c4) at ( 6,-1.5) [bag] {$\textrm{Mean} = \ln r_{20} + \dfrac{3}{2}\sigma_2\sqrt{\Delta t_2}$\\$\textrm{Mean Change} = \mu_{11}\Delta t_2 = \ln\dfrac{r_{20}}{r_{10}} + \dfrac{3}{2}\sigma_2\sqrt{\Delta t_2} - \sigma_1\sqrt{\Delta t_1}$}; \node (c5) at ( 6,-3) [bag] {$\ln r_{20}$}; \draw [->] (a) to node [below] {} (b1); \draw [->] (a) to node [above] {} (b2); \draw [->] (b1) to node [below] {} (c1); \draw [->] (b1) to node [below] {} (c2); \draw [->] (b1) to node [below] {} (c3); \draw [->] (b2) to node [below] {} (c3); \draw [->] (b2) to node [below] {} (c4); \draw [->] (b2) to node [below] {} (c5); \end{tikzpicture} \end{center}  \end{document}       Update code use  \draw [->] (a) to node [below] {} (b1.south east); \draw [->] (a) to node [above] {} (b2.north east); \draw [->] (b1.south east) to node [below] {} (c1.west); \draw [->] (b1.south east) to node [below] {} (c2.west); \draw [->] (b1.south east) to node [below] {} (c3.west); \draw [->] (b2.north east) to node [below] {} (c3.west); \draw [->] (b2.north east) to node [below] {} (c4.west); \draw [->] (b2.north east) to node [below] {} (c5.west);


I want to create a Shorcut which execute a code when clicked

I want to create a file, which will execute a code in terminal when dbl clicked.. Can this be done? If Yes, How?


How do I reference a publication in my CV where I am alphabetically listed as an author but the citation lists the organization?

I recently was part of a large writing group that produced a publication. Authorship, including myself, is listed alphabetically in the acknowledgements however the group leadership chose to list the organization as the author in the citation/reference rather than acknowledge contribution for authors. I previously brought this up as a problem when there was a proposed order of authors and sent the group leadership standard criteria for authorship listing.  How can I list the publication in my CV?


Transit Visa requirement for San Francisco to Cape Town via London

Do I need a visa for a 7 hour layover as I have South Africian passport on route from SF to London to Cape Town


Can files and directories under C:\Users\\AppData\Roaming be safely removed?

I was looking at what files are on my hard disk, and saw that  C:\Users\<username>\AppData\Roaming has over 1 GB worth of files under it (found by a dir /s/a  command).  What is the purpose of this folder, and is it okay to delete the files and folders under it, or not?


How does the mechanism for pushing a question to the reopen queue work?

It seems that there are many ways to get a question into the reopen queue, how does it work?  When a question would be pushed to the queue? When a question wouldn't be pushed to the queue?


I have experienced this problem every single time I have tried to compile using XeLaTeX with MiKTeX 2.9 on my windows 7 64-bit machine. I haven't been able to find a solution to my problem anywhere so I am just going to describe it the best I can here with the hope that someone will know what to do.  When I try to typeset using XeLaTeX, I get the following pop up:  The required file  tex\xelatex\xetexurl\url.sty   is missing. It is a part of the following package:  xetexurl   I then have to install the package from a random package repository. The file is typeset correctly. I then make some edits and need to typeset the file again. I get the same pop up. Interestingly, at the bottom of the pop up, I have the box checked that states: "Always show this dialog before installing packages." I finally decided to uncheck that box and something interesting happened: I could not typeset a document again using XeLaTeX; the "Process crashed" every single time. I changed my MiKTeX settings to have the program always ask me first and I can now typeset documents again using XeLaTeX, but the pop up always shows up. I thought this question was similar:   But it has not really helped. I wonder if I am not alone with this issue. It has started to become a real nuisance. Any ideas as to what I can do to avoid having to install this package every single time when typesetting?


The problem is: A group of people met and some of them (NOT all of them) shook each other hands. Prove that the number of people who shook others' hands an odd number of times is even.  My attempt:    I have already shown the cardinality of the group of people must be finite, since saying infinity is even doesn't make sense. I tried to use the method of graph theory. But I encountered a critical problem that "the member of people who shook others' hands an odd number of times" can shook hands with "the member of people who shook others' hands an even number of times".   I thought the condition was "all of them shook each other hands", which is a easy case. But this one seems harder. I cannot figure it out. Any help will be appreciated.


Utility to FORCE a Windows desktop to lock after  minutes of inactivity (screensaver unreliable)

Title says it all, it seems my Windows 7 workstation doesn't always respect the screensaver settings, is there a secondary utility that would be able to forcefully lock the workstation after a certain amount of inactivity?


ipa-server failed to make a configuration?

I want to make a configuration for ipa-server on Centos 7. But I can't do it as I get this message:  DNS zone example.com already exists in DNS and is handled by servers: ns1.uniregistrymarket.link ns2.uniregistrymarket.link   What I did:   Configure 192.168.10.10 server1.example.com in /etc/hosts  ipa-server-install    But I got this message.  Any help!


Why are there so many users with low "reputation" points?

I see that many of the questions posted all have really low reputations points, from 1-50.  Given that you get points for simply editing and selecting answers, I find this hard to believe.  It makes me less likely to want to answer questions as it seems these users create accounts just to mine information and then open up another account for their next question.  Why not give users more incentives to use the site as an actual user and not just a place to mine information?  For example - the ability to delete down-voted posts, the ability to block users (trolls, etc.).  Basically any of the things popular social sites have?


Show that $\lim\limits_{n \to \infty} \sup\limits_{k \geq n} \left(\frac{1+a_{k+1}}{a_k}\right)^k \ge e$ for any positive sequence $\{a_n\}$

Show that $$\lim_{n \to \infty} \sup_{k \ge n} \left(\frac{1+a_{k+1}}{a_k}\right)^k \geq e$$ for any sequence $\{a_k\}$ with positive terms, and that this estimate cannot be improved. Let $$s_k = \left(\frac{1+a_{k+1}}{a_k}\right)^k $$  Then $s_k \geq 0$ as otherwise $a_{k+1} < -1$. Also, $\sup_{k \geq n}\{s_k\}$ is nonincreasing on $n$. Assume $\lim\limits_{n \to \infty}\sup_{k \geq n}\{s_k\} = l < e$. For $0 < \varepsilon< e-l $, choose $N$ such that $l \leq \sup_{k \geq n}\{s_k\} < e - \varepsilon$ for all $n > N$.  We know that $$\lim\limits_{n \to \infty} \left(\frac{n+1}{n}\right)^n = e$$ and that $r_n = \left(\frac{n+1}{n}\right)^n$ is increasing. Choose $N'$ such that $e- \varepsilon < r_n < e$ for all $n > N'$.  Then for $M =\max\{N,N'\}$, $ \sup_{k \geq n}\{s_k\} <r_n$ for all $n>M$. Furthermore, $s_n \leq \sup_{k \geq n}\{s_k\}$, so $s_n < r_n$.  Here I wanted to get some sort of contradiction but I'm not really sure how. I know that $a_n$ cannot have a limit $A$ as then $$0 \leq \lim\limits_{n \to \infty} a_{n+1} < \lim\limits_{n \to \infty}\left(1 + \frac 1n \right)a_n -1,$$ which implies $A < A-1$  And $a_n$ cannot be bounded by $d$ as we would have, for  $n > 2d$, $a_{n+1} < a_n\left(1 + \frac 1n\right) - 1 < d\left(1 + \frac {1}{2d}\right) - 1 = d - \frac 12$. Continuing in this way there would be an $a_n < 0$.   I was thinking of using the fact that the superior limit is the largest partial limit. What should I do next or should I use a different method?


Another way to increase Tungsten filament resistance?

I understand that the thing that allow a lightbulb to glow white high is the fast amount of resistance the electrons face with all the many spiral the filament has. But I need a thicker more resistant filament so is there another way to increase resistance?


Can I use an "if" clause without "then"?

I have the following sentence:     If T had still been alive, there is the great possibility that either T or C ...   My teacher says that the word "then" must appear after the comma, but I think that it's implied and unnecessary. Who is right?


onclick doesn't work in admin widget for Wordpress

in admin panel when I add a widget to the page the javascript doesn't execute. Here is code for my plugin:  class Mosaic extends WP_Widget {     // class constructor     public function __construct() {         $widget_ops = array(          'classname' => 'Mosaic',         'description' => 'Widget provides mosaic jquery.',         );         parent::__construct( 'mosaic', 'mosaic', $widget_ops );       }      // output the widget content on the front-end     public function widget( $args, $instance ) {         echo $args['before_widget'];         echo $args['after_widget'];     }      // output the option form field in admin Widgets screen     public function form( $instance ) {         wp_enqueue_media();     ?>

test1

test12

test122

     <?php     }      // save options     public function update( $new_instance, $old_instance ) {}    }  add_action( 'widgets_init', function(){register_widget( 'Mosaic' );}); function my_enqueue() {     wp_enqueue_script( 'mosaic-js', 'mymosaic.js' ); } add_action( 'admin_enqueue_scripts', 'my_enqueue' ); wp_enqueue_script( 'mosaic-js', '/wp-content/plugins/mosaic/mymosaic.js', array( 'jquery' ), '0.0.1', true );   and javascript is simple, based on Jquery:  jQuery( document ).ready( function( $ ) {         $('.ui-state-default').click(function() {           alert( "Handler click called." );         }); });   If I put it in javascript alert function, it works fine. But everything else, like click doesn't work, could you help me with the issue?


The dimension of a subspace is less than dimension of the whole space.

Let $X$ be topological space and $Y\subset X$. The goal is to show that $\dim Y\leq \dim X$.   Here we use this definition of dimension.  Let $Y_0\subsetneq Y_1\subsetneq \cdots \subsetneq Y_{n}$ be a chain of strictly increasing closed irreducible subsets of $X$ then $\dim X$ is the supremum over all such chains.   This is what I've got so far. I'm just stuck on one last bit. A hint would be nice.   Let $Y_0\subsetneq Y_1\subsetneq \cdots \subsetneq Y_n$ be a chain of irreducible closed subsets of $Y$. Since each $Y_i$ is irreducible, we just need to close them in $X$. There exists $F_i$ closed in $X$ such that $Y_i=F_i\cap Y$. Then if we closed each set in $X$, $\overline{F_0\cap Y}\subset\overline{F_1\cap Y}\subset \cdots \subset \overline{F_n\cap Y}$ is a chain of irreducible closed subsets of $X$. I just need to show that they are distinct. I really don't know where to proceed. A hint would be appreciated. Thanks.


Control how tight / loose a mesh will be to a vertex

How to control in Blender 2.8 how tight a mesh will be to a vertex. I thought it was vertex weight but after several tries no success. As you can see in the example image, the mesh follow the vertex ponted with green arrows in a loose fashion while those marked with red arrows fully "atract" the mesh.


I've seen too many newbies hit the "quote" button instead of the "code" button while posting. This is much worse than if they just left the code inline, because the quote button rewraps all the text and saves the post with mangled code.  For example, here's some (bad) C++:  class X{};  X& foo() {     X x;     return x; } int main() {     X &x = foo(); }   and some quote-mangled C++:  > class X{}; >  > X& foo() {    X x;    return x; } int main() {    X &x = foo(); }   Once they've saved the post, it is impossible to recover the original formatted code without a substantial amount of effort. One user  producing an unreadable mess, not realizing that "quote" was the wrong function for a nicely-formatted stacktrace.  I understand the holdover from email, but it seems unnecessary for StackOverflow to rewrap given that quoted text renders essentially identically to unquoted text (aside from being enclosed in a <blockquote>). It seems to me it would be easier to have the quote button just prefix >  to each selected line, kind of like how the code button prefixes     , and leave it at that.  So the question is: why does the quote button have to rewrap text when you push the button?    For reference, here's how quoted text appears, first using the quote button and second by manually prefixing > :     class X{};      X& foo() {       X x;       return x; } int main() {       X &x = foo(); }   and     class X{};      X& foo() {       X x;       return x;   }   int main() {       X &x = foo();   }   The appearance is identical, but the latter quote can actually be reversed into proper code later on.


Logic: Using Quantifiers To Express "At Least 2?"

Let $been(x,y)$ denote "person x has been to place y."   Express “Every person has been to 2 or more places” using quantifiers and $been(x, y)$.  This one is completely stumping me. I'm sure that I haven't come across this kind of concept before, and can't wrap my head around how I would approach it. I suspect the quantifiers should be $∀x$, $∀y$, and that it may involve negating the statement "every person has been to one or zero places," but that's as far as I can manage to go. Any help greatly appreciated.


First of all, I swear this is not homework, it's a question I was asked in an interview. I think I made a mess of it (though I did realise the solution requires recursion). Here is the question:  Implement the count() method which returns the number of nodes in a tree. If a node doesn't have either a left or right child, the relevant getXXChild() method will return null  class Tree {    Tree getRightChild() {     // Assume this is already implemented   }    Tree getLeftChild() {     // Assume this is already implemented   }    int count() {     // Implement me   } }   My reason for asking the question is simply curious to see the correct solution, and thereby measure how bad mine was.  Cheers, Tony


How is a continuous Fibonacci number $F_n$ defined? (like the Gamma function for factorials) Tried with Binet's formula (Wiki) , but to no luck. F[n_] = N[GoldenRatio^n - 1/GoldenRatio^n]/Sqrt[5] Plot[F[n], {n, 3., 12.}, GridLines -> Automatic] FibonRatio[n_] = N[Fibonacci[n + 1]/Fibonacci[n]]; Plot[{FibonRatio[n], N[GoldenRatio], 1.7}, {n, 3., 12.},   GridLines -> Automatic]  Also using this continuous function definition how is it proved that $$\lim _{n\rightarrow \infty}\dfrac{F_{n+1}}{F_n} = \phi$$ ( where $\phi$ is the GoldenRatio) ? Appreciate your comments.


I'm with Ubuntu 15.04 and I'm trying to create an emulator (genymotion), but when run virtualbox, i got the error:     Stopping VirtualBox kernel modules ...done.   Uninstalling old VirtualBox DKMS kernel modules ...done.   Trying to register the VirtualBox kernel modules using DKMSError! Your kernel headers for kernel 3.16.0-30-generic cannot be found.   Please install the linux-headers-3.16.0-30-generic package,   or use the --kernelsourcedir option to tell DKMS where it's located    ...failed!     (Failed, trying without DKMS)   Recompiling VirtualBox kernel modules ...failed!     (Look at /var/log/vbox-install.log to find out what went wrong)   I performed   uname -a   And the result is:     Linux douglas 3.16.0-30-generic #40-Ubuntu SMP Mon Jan 12 22:06:37 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux   Someone help me?Already I uninstalled and installed again.


How can i Convert an string to double but with power of 10

I'm stuck with a problem and I have to display these numbers correctly using the power of ten. I know that the number in the end has to do with the fact that the decimal point is shifted the number to the right, only how I can do it or how I have to parse the number is a mystery to me. I have the numbers as a string The whole thing is written in C # "1.11632e+007" "1.30357e+008" The result must look like this The output can be as int or string does not matter 11163200 130357000 I have no idea how to do this. Can you help me?


How to execute one command on all files within a folder

Saying, I have this tree and I want to execute ruby on all scripts within the folder. How could I archive through one line of command.   ./ ../ rb-script/     sample1.rb     sample2.rb


Let $X= \{ A \subset \mathbb{N} : \mathbb{N} \backslash A \text{ is finite}\}$. What is the cardinality of $X$? Prove it.  For me the cardinality should be the same as the natural numbers. I am trying to show a way of ordering it, the first A is one with the smallest numbers and so on.


Most articles of my site contain huge revisions. It is very tedious and annoying to delete huge revisions one by one following the url ,say, www.example.com/node/9022/revisions. I want to implement an interface in Admin panel to delete multiple revisions at one time. But dont know how to implement this concept. Plz help


How to wake up the blue alpaca in Animal Crossing New Leaf?

In my Re-Tail shop, there is a blue alpaca who appears to be Reese's fiance. When I try to wake him up, Reese says that he is tired from working all night on something. How do I wake him up and what is he for?


How to Render Attachments (images) in visualforce

I have attachments (images) for an object and here's how I am querying for my data from the object.   public List<SObject> getResults () {     Id id = ApexPages.currentPage().getParameters().get('id');     List<SObject> results = [SELECT Id,                                      Name,                                      URL__c,                                     (SELECT Id, Name FROM Attachments)                                     FROM MyCustomObject__c                                      WHERE                                      Id = :id];     return results; }   This is how I am rendering this data in visualforce  <apex:repeat var="c" value="{! results }">
                     {! c.Name}
                  <apex:outputText rendered="{! c.URL__c != null }">
URL

                         {! c.URL__c}
                 </apex:outputText> </apex:repeat>   How can I render the attachments similar to how I am rendering URL__c and Name?


Why do some lenses cost 10 times as much when the specs are very close?

For example, a  is about US$110, while another  is about 14 times as expensive, at about $1450.  Is the 1.8 or 1.2 the main reason for the price difference?  The same goes for some variable lens, such as , and , which costs several times more.


Looking for a Pre-1975, young adult, sci-fi, colored circle dimension crossing

Looking for the title and or author of a long ago favorite; I have searched the web for it on and off for years.  I read a paperback novel about 40 years ago; it was probably a used book at that time. Probably pre-1975 publication.  In my memory it was written in the style of Andre Norton I have looked through her , but I am not finding it. It was a young adult sci-fi novel.  Plot; a young woman (gender was not strong, but I remember the main character being female) can see different colored circles floating around. When she looks at them just right, she can jump through to another universe.  In the other universe, things change.  She might become a lion, or maybe she is carrying a seed that becomes a net in the other universe.   Two bad guys are chasing her around the different dimensions, I recall one scene where they are all sliding down an icy slope and she jumps through a portal, to escape the bad guys.   There were a lot of complexities about, dimensions, what became what, different colors of portals and such.


I'm sorry if this isn't the place to ask this, but there doesn't seem to be a web security stack exchange site, so this looks like the closest thing to me. If there's a better place to put this question please let me know.  I'm using Firefox on Ubuntu and I accidentally clicked an ad that took me to an obvious scam site. There's no changed behavior on my computer, but just to be safe I'd like to know what you should do after visiting an unsafe site. Thanks


how do you add users input from multiple entries, and add them together

Example  ballEntry = Entry(window,width=10, textvariable=total) TenisballlEntry = Entry(window,width=10, textvariable=total)   total =  ballEntry.get() + TenisballlEntry.get()   I don't know how to take the input from the what the users enter, and then sort of "turn them" into an integer that the program can understand so they can be added?


How to trim this cylinder where it meets a box

I have a box that I have extruded to the shape I want. Then I placed a cylinder so that it intersects the box. After that I deleted the bottom faces of both the cylinder and box.  Now what I want to do is delete the portion of the cylinder that is inside the box and join the nodes so that it is one object. I have already joined the meshes so I can select points/edges/faces from either shape. It seems like the easiest way would be to just put nodes where the edges of the cylinder and box intersect and then delete the parts I don't care about. I can't find a good way to do that though.  What's the best way to accomplish what I'm trying to do?


add'l quesion to Installing Ubuntu Into a Virtual Machine.

I have followed all of the proceedures listed in the aforementiond answers to this question with some success. Only, Everytime I boot up the VM, it asks me to either Try Ubuntu or Install it. Why can I not simply work on the system? I've started installing it only to cancel out and seem to be able to work with it some there, but still, this seems wrong/broken. Any Help Please??


Proving that point of intersection of diagonals of trapezium lies on the line passing through the midpoint of parallel sides?

Can someone tell me the steps to solve this problem?     Prove by vector method that the point of intersection of diagonals of   trapezium lies on the line passing through the midpoint of parallel   sides.   I assumed the ratio of division of diagonals at intersection point as $a:1$ and $b:1$ and wrote the position vectors of the intersection point in terms of $a$ and $b$.But i'm getting too many variables.Any easier way out?


Would it be possible to screen capture or output node-tree network like really big, bigger than actual monitor screen. If possible, a way to capture the node-tree boundary.  So far, I only screen shot limited to my monitor.  Thanks.


How to get the round off value of a decimal in C#

I want to get the round off value of a decimal number Suppose I am getting 24.86 than i want to get 25 as final value


I want to count points (1000 of students home) in district polygons with Qgis 2.16. I didn't find the tool in the analysis tools plugin.   Is there another plugin or method I could use to perform this task ?


Since we have already found out , why not take a stab at how again should be enunciated?  Obviously, there are some words where both of two pronunciations are valid. Take the, for example. The word is usually pronounced /ðə/, but becomes /ði/ if it precedes a vowel or vowel sound.  What about /əˈɡɛn/ versus /əˈɡeɪn/? Is one more valid? Are both valid, but in different circumstances?


How to auto approve Salesforce REST API OAuth2 authorization flow to not show "Allow Access" pop-up

Currently, I am using OAuth2 authorization code flow to authenticate REST services, but when i am doing request to get authorization code like  But it required the login & allow access then it redirects to my callback URL with accessCode. So I want to skip this process & auto-approve it because I am using it as background service & not interacting with the user. So how to auto-approve Salesforce REST API OAuth2 authorization_code flow to not show allow pop-up.


UPDATED: Why have I worked so much with URL rewriting when I can't accomplish a very small feat?

The originally intended title exceeds the limit; it is, "Why is a URL shortener rewriting  to  when I want  forwarded to ?"  I posted below a question asked after long using Apache URL rewriting (from 1.3.x when 2.0 wasn't around). A quick check shows my /etc/apache2/sites-enabled to have 121 RewriteRules, including site relocation, switching from HTTP to HTTPS, and other workhorses. I'm also having trouble with a very simple task, simple as putting a RewriteRule to move something to another URL without breaking links or causing the old location to be a 404 error.  I also sanitized servers and identifiers, not because I'm relucant to give this specific raw data, but in an attempt at politeness, partly to avoid spam, and partly because someone can always ask to see the real data.  I have, modulo removing comments and hiding masking e.g. domain names, the following Apache VirtualHost:  <VirtualHost *:80>         ServerAdmin cjshayward@pobox.com         DocumentRoot /home/jonathan/stornge         ServerName cjsh.name         ServerAlias www.cjsh.name         LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-agent}i\"" combined         CustomLog /home/jonathan/logs/stornge.com combined         RewriteEngine on         #RedirectMatch ^/$ https://cjshayward.com/books/         RewriteRule ^/$ https://CJSHayward.com/books/ [R=301,L]         RewriteRule ^$ https://CJSHayward.com/books/ [R=301,L]         RewriteRule ^/([^?].*)$ http://stornge.com/?$1 [R=301,L]         #RewriteRule ^.*/writings/autobiography/(.*)$ /about/author/ [R=301,L]         #RewriteRule ^/tiki.*$ http://www.facebook.com/pages/CJS-Hayward/9506801167 [R=301,L]         #RewriteRule ^/community/tiki.*$ http://www.facebook.com/pages/CJS-Hayward/9506801167 [R=301,L]         <Directory /home/jonathan/stornge/>             Options ExecCGI Indexes FollowSymLinks MultiViews             AllowOverride None             Order allow,deny             allow from all         </Directory> </VirtualHost>  I'm not sure this is anywhere near optimal; the reasons for involving two servers (for an external site not hosted on either server, three) are mostly historical that could be improved on.  However, I want  to redirect to , and every time I load the homepage at , I am redirected to the homepage for  as a whole.  I can put the URI referral script in a pastebin if others want to see it, but I put what was meant as a "redirect from homepage" URL shortener:  #!/usr/bin/python   import cgi import cPickle import os import re import sys  if (os.getenv('HTTP_HOST') in ['cjsh.name', 'www.cjsh.name', 'stornge.com',   'www.stornge.com' and os.getenv('REQUEST_URI') ==   os.getenv('SCRIPT_NAME')):     print '''Status 301 Moved Permanently Location: https://CJSHayward.com/books/ Content-Type: text/html; charset=UTF-8  Go to bookstore.'''     sys.exit(0)  I've tried a couple of ways of working around it, with clearing caches, switching between browsers, and using (sub)domains I haven't really used for anything else; I don't really use a FQDN of  unless I was trying to circumvent caching expected in .  I do not consider this question to be, "How do you get things basically working with URLs and get work done," but "Why do my quite numerous attempts to redirect  to  end up at the  homepage? These are two very different questions, so far as I know.


Where to see logs of device connecting/disconnecting events in Windows?

When I connect devices to my Windows machine, the "upwards" sound is heard. When I disconnect it -- the "downwards" sound is heard.  Is there a way to find events, corresponding to these sounds in event viewer?  I want to see what device was connected and how successful it was.  UPDATE  This is USB device.


Solutions to $\int\limits_x^{x^2} f(t)\ dt=\int\limits_1^x f(t)\ dt$?

Supposing that $f(x)$ is continuous for positive values of $x$, what are the solutions to the equation $\int\limits_x^{x^2} f(t)\ dt=\int\limits_1^x f(t)\ dt$?  Attempt: We can write the LHS as $F(x^2)-F(x)$ for $F$ an antiderivative of $f$  We can write the RHS as $F(x)-F(1)$  So we have $F(x^2)-F(x)=F(x)-F(1)$. Now differentiate both sides,  $2 x f(x^2) - f(x) = f(x)$ Solve:  $x f(x^2) = f(x)$  Now, it seems like fucntions of the form $f(x)=\frac{c}{x}$ would solve this, but are these the only ones?


Minecraft Not enough Items cheat mode disabled

So I was making a modpack with only 10 mods (WIP) and one of them happened to be Not enough items 1.6.1.9. I loaded up my modpack and loaded the world. The mods seemed to be working just fine. NEI was also working but when I switched the mode to cheat mode, it was still in recipe mode... My lockmode is set to -1 but its still stuck in recipe mode. Also, there are no tools in the upper left hand corner for cheat mode and "gamemode" is disabled.


What is the conceptual difference between posterior and likelihood?

I have trouble discerning conceptually between these two notions. I am aware of their formal relations, proprieties and what not, but I just can't wrap my head around what they "mean", if that even makes sense. I have checked some answers, such as , but I think none of these addresses my problem.  So, given some data $\mathcal{D}$ and parameters $\theta$,  $$ p(\theta|\mathcal{D})=\frac{p(\mathcal{D}|\theta)p(\theta)}{p(\mathcal{D})} $$  I have learned that the posterior is "the probability of $\theta$ being the statistical parameter underlying $\mathcal{D}$". And the likelihood is "the likelihood of $\theta$ having generated $\mathcal{D}$". In my head, these two notions are exactly the same. So how can I distinguish them?


Exporting Picklist Values and the combinations

We have 3 different picklist fields in our Case object  Queue/Type/Area   Queue controls Type values. Type controls Area values.   I would like to know whether there is a way to export picklist values in the following format from the application depending upon the controlling-dependent field mappings.  For Example  Queue values are : {Q1,Q2,Q3}  Type values are  : {T1,T2,T3}  Area values are  : {A1,A2,A3}  Contolling-dependent mappings are as follows  Queue-Type mapping  {Q1-T1}  {Q2-T2}  {Q3-T3}  Type-Area Mapping  {T1-A1}  {T2-A2}  {T3-A3}  My desired output should be   {Q1-T1-A1}  {Q2-T2-A2}  {Q3-T3-A3}  I am okay if the solution is obtainable via code also.  Can someone throw me some pointers as to how can I achieve that ?


Starting a fire with a lens without the sun

I am curious about the ability for a lens to start a fire without using sunlight. Is it possible for alternative light sources (LED, incandescent, etc.) in combination with a very large Fresnel to start a fire? Or more appropriately how much energy could a very large Fresnel lens concentrate into one point using everyday light sources?  In considering different types of light sources, which would be best for generating the most heat? Luminous efficacy and the size of the light source seem the most obvious but how would the color of the light affect the lens' ability to generate heat?  Will a high focal length and large aperture lens (such as a giant spot Fresnel) even be able to focus the amount of light sources necessary into a small enough point to generate enough heat?


In , after the battle, inside Winterfell, the giant is on his knees and Jon Snow is standing besides him when Ramsay strikes the giant in the eye with an arrow. The giant was already fatally wounded and was unlikely to get back on his feet. Why did Ramsay aim for the giant then and not Jon Snow?


Why is my PostgreSQL expression index not being used when I ORDER BY in a subquery?

I have a query that gets about 80k rows from said table with about 3m.  I only need to paginate ten rows at a time, but with ORDER BY (a+b) DESC (a and b are integer type columns.)  Right now my query's taking about 4 seconds to do this.  If I ORDER BY the primary key instead, it avoids seq scans and takes 200ms, which I would be happy with.  So I created an index on (a+b) DESC.    My thinking there is that the ORDER BY and primary key both have indexes (as do all the things in the WHERE clause--and those indexes are being used just fine), so the subquery should be able to accomplish everything it needs to without a seq scan, give up 10 indexed primary keys to the outer query, which, if it needs a seq scan because of the *, only needs to find ten rows.  It didn't make a difference, anyway.  Unfortunately, I can't share full table details, but I can say that my table has 21 columns, with some text, two integer, several timestamps and even one ts_vector. Aside from the expression one there are 4 indexes: the PK (text) is btree, I have another btree text, a btree timestamp, and a gin index on the tsvector.  Further: I can also order by the indexed timestamp and the non-primary-key indexed text, and just like the primary key, this reduces query time to 200ms thanks to index usage.  It's just my expression index that doesn't seem to work this way in the subquery context.  Other options, none of which seem great:   Add a computed column for (a+b) so the index is just on one column.  If it works for ORDER BY on the pk it should work for that column, right? Cheat by somehow guesstimating a happy limiter on (a+b) due to its distribution.  I'm not sure how I would always know because the query inputs are dynamic, but in this case, if I add a simple AND (a+b) > 1000000, I still get ten rows back but it only takes 200ms--and uses my expression index for the WHERE clause where the seq scan would normally be.  (About the not knowing, I could start doing some kind of binary-search-esque thing, trying high numbers and reducing by half until I get at least 10 rows back and then calling it a day.  If I get it within less than 20 tries, I'm still ahead.  But this is beyond kludgy...)   Any ideas?  How can I get it to use my expression index and avoid a seq scan?  The reason I don't understand the above is that the docs (going back to 9.4 at least) explicitly put it this way:     Index expressions are relatively expensive to maintain, because the derived expression(s) must be computed for each row upon insertion and whenever it is updated. However, the index expressions are not recomputed during an indexed search, since they are already stored in the index.   So how on earth is other_column any less expensive to ORDER BY than a+b when both are indexed?    Regarding query plans, let's try to get to the heart of it.  I've posted .


I have a shell script that prints the first argument passed to it in the command line. I was experimenting with $1 and "$1". Interestingly to me, when I pass "John Doe" I get different outputs. hw Version1 #!/bin/bash printf "Hello %s\n" $1  Result is the following. Seems like it loops through strings separated by space: $ hw "John Doe" Hello John Hello Doe  hw Version2 #!/bin/bash printf "Hello %s\n" "$1"  Result is: $ hw "John Doe" Hello John Doe  what is the difference between $1 and "$1" when the argument in the command line is something like "string1 string2 ... stringn"?


Opening the door to the first house on the left in the village in Candy Box 2

I want to know what is inside, but I don't know how to open the door! How can I open it?


Why if H⊴G and H is solvable and G/H is solvable, then G is also solvable?

Plus, to the proof any p-group G is solvable,although Z(G) is normal to G and which is abelian, but G/Z(G) is not abelian, so what is the chain subgroup to  show that G is solvable?


Can't get this piece of code to pass. Can someone please help me

I don't know why this piece of code is not passing. Return true if each sub-list is individually in ascending order, false otherwise. public static boolean allSubListsAscending(ArrayList<ArrayList<Integer>> list) {          for (ArrayList<Integer> intList : list) {             for (int j = 0; j < intList.size() - 1; j++) {                 if (intList.get(j) > intList.get(j + 1))                     return false;             }          }         return true; }  @Test @Graded(description="AllSubListsAscendingComprehensive")     public void testAllSubListsAscendingComprehensive() {         testAllSubListsAscendingBasic();         assertFalse(ListOfListService.allSubListsAscending(null));         assertFalse(ListOfListService.allSubListsAscending(list4_nullItems));          ArrayList<ArrayList<Integer>> ascending = new ArrayList<ArrayList<Integer>>();         ascending.add(new ArrayList<Integer>(Arrays.asList(10, 20, 70, 90)));         ascending.add(new ArrayList<Integer>(Arrays.asList(100, 110, 120, 130)));         ascending.add(null);         ascending.add(new ArrayList<Integer>(Arrays.asList(10, 20, 70, 90)));         assertFalse(ListOfListService.allSubListsAscending(ascending));          currentMethodName = new Throwable().getStackTrace()[0].getMethodName();     }


Need my for loop to wait once my function return value till it go to next iteration

I am using a loop in my function which is calling another function I wanted it to wait till I get the result then go to next iteration.I am using promise but it is not working as well. Marked ** in that portion.    function imagecheck(url) {     return new Promise(function(resolve, reject){         var img = new Image();         img.onload = function(){             resolve('success');         }         img.onerror = function(){             reject('failure');         }         img.src = url;     }); }  function getcheck(Id) {     var j=0;     var myId = Id;     var myimages = [];     **for(var i=0;i<=j;i++)    {         var imageUrl = 'someprexixurl'+myId+'&page='+j;            this.imagecheck(imageUrl).then(function(successUrl){             myimages.push({url:imageUrl});             j++;         }).catch(function(errorUrl){              });    }** }


If $x$ is the cosine of the angle between the vectors $a$ and $b$, $y$ is the cosine of the angle between the vectors $a$ and $p$, and $z$ is the cosine of the angle between the vectors $b$ and $p$, can we write $z$ in terms of $x$, $y$ and the magnitudes of $a$, $b$, and $p$?   That is, no dot products should appear in the relation.  All vectors are in $4$-dimensional Euclidean space.


issue in converting hexadecimal to byte array

i have string like     string test = "0x527AE53437CAED39D3E2A8B3E90FFC3BA9073B6D933BC05FF6677B5521DC34"   How can i convert the string to byte[]?


From Wiki and from physics fundamentals lections I received info that  is scalar value. But in definition you have relation between projections of two vector values to normal axe-force and surface area with normal orientation. Are you interesting only in absolute values of this two vectors? (if so then the pressure is always positive.)   Can pressure be negative?  I don't want to discuss the averaged model of the pressure compare to tension elastic model.  At current moment from the post answers and comments I realized that pressure scalar field can be defined so:    $f$ is support force to support equilibrium in $ds$ surface under other molecules attack. pressure scalar value in some circumstances can be negative. If smth. was wrong here please let me know!


403 forbidden error in Apache with document root on an NTFS partition

I'm a beginner in Ubuntu hoping to find a better web development environment than WIndows. I'm trying to access http://localhost but its always giving me a forbidden error. I've installed php, mysql, and apache separately. Files/web_files is also my web directory in windows which when I access on windows is D:/Files/web_files and on ubuntu is media/Files/web_files. I also restart apache after editing the default file located in etc/apache2/sites-available Am I editing the wrong file? Please help.  <VirtualHost *:80>     ServerAdmin webmaster@localhost      DocumentRoot /media/Files/web_files     <Directory />         Options FollowSymLinks         AllowOverride None     </Directory>     <Directory /media/Files/web_files/>         Options FollowSymLinks         AllowOverride All         order allow,deny         allow from all     </Directory>      ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/     <Directory "/usr/lib/cgi-bin">         AllowOverride None         Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch         Order allow,deny         Allow from all     </Directory>      ErrorLog /var/log/apache2/error.log      # Possible values include: debug, info, notice, warn, error, crit,     # alert, emerg.     LogLevel warn      CustomLog /var/log/apache2/access.log combined      Alias /doc/ "/usr/share/doc/"     <Directory "/usr/share/doc/">         Options Indexes MultiViews FollowSymLinks         AllowOverride None         Order deny,allow         Deny from all         Allow from 127.0.0.0/255.0.0.0 ::1/128     </Directory>  </VirtualHost>   Update If I used var/www instead it works like magic.  DocumentRoot /var/www <Directory />     Options FollowSymLinks     AllowOverride None </Directory> <Directory /var/www/>     Options FollowSymLinks     AllowOverride All     order allow,deny     allow from all </Directory>   Here's the output from the mount command  /dev/loop0 on / type ext4 (rw,errors=remount-ro) proc on /proc type proc (rw,noexec,nosuid,nodev) none on /sys type sysfs (rw,noexec,nosuid,nodev) none on /sys/fs/fuse/connections type fusectl (rw) none on /sys/kernel/debug type debugfs (rw) none on /sys/kernel/security type securityfs (rw) none on /dev type devtmpfs (rw,mode=0755) none on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620) none on /dev/shm type tmpfs (rw,nosuid,nodev) none on /var/run type tmpfs (rw,nosuid,mode=0755) none on /var/lock type tmpfs (rw,noexec,nosuid,nodev) none on /lib/init/rw type tmpfs (rw,nosuid,mode=0755) /dev/sda2 on /host type fuseblk (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other,blksize=4096) binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev) gvfs-fuse-daemon on /home/wern/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=wern) /dev/sr0 on /media/2022_21092011 type udf (ro,nosuid,nodev,uhelper=udisks,uid=1000,gid=1000,iocharset=utf8,umask=0077) /dev/sda3 on /media/Files type fuseblk (rw,nosuid,nodev,allow_other,blksize=4096,default_permissions) /dev/sda1 on /media/System Rese   And here's the output from ls - laR/media  ls: cannot access -: No such file or directory ls: cannot access laR: No such file or directory /media: 2022_21092011  Files  System Reserved   So I'm wondering if this is an issue in the filesystem or its permissions. But I don't think it has something to do with permissions since I can perfectly edit the files in media/Files/web_files without having to run it as a superuser.  Thanks for those who has taken their time to help me so far.


How can we shorten a URL with Dynamic variable in SFMC using bitly

I am trying to create an SMS message for customers to pass their last ordered number in a URL as a dynamic value so on click the customer will be redirected to the cart page. The entire URL looks very long and we would like to cut short it like bitly links. As far I know bitly can cut short only static URLs but not the URLs with dynamic values. Is there a way to cut short the URL that has dynamic value in it?


Java JComboBox listen a change selection event

I'm trying to listen to a change of selection in a Java JComboBox. I have tried to use an ActionListener but the problem is this: the action listener does something like this   public void actionPerformed(ActionEvent e){     JComboBox<String> source = ((JComboBox<String>)e.getSource());     String selected = source.getItemAt(source.getSelectedIndex());      /*now I compare if the selected string is equal to some others        and in a couple of cases I have to add elements to the combo*/ }   As you can notice, when I need to add elements to the combo another event is fired and the actionPerformed method is called again, even if I don't want that, and the code may loops... :( Is there any way to listen to the selection change only and not to a generic change event? Thanks


What camera should I buy and what do I need to look for?

I want to start photography as an hobby. So to start I need a camera. I now a reflex would be the best, but I have no idea what to look for: pixels or ISO. What would the most adapted lens for landscape pictures. I'm ready to spend a maximum of 500$ in a camera.


Using tar, is it possible to compress stdin text and have the compressed data appear in stdout? Example:  $ echo "test" | tar c -  <compressed blob here>   I'm using macOS Mojave.


I have pressed Shift-Cmd-4 and selected an area. Now it is in screen capture app. But I need it inside clipboard to paste here. How to do that?


How can I compress image PNG And JPG images?

How can I compress PNG and JPG images by more than 50%?


How to calculate the limit: $\lim_{n\to\infty}\sum_{k=1}^n\big(\frac{k}{n}\big)^n$

How to calculate the following limit?$$\lim\limits_{n\to\infty}\sum\limits_{k=1}^n\left(\frac{k}{n}\right)^n$$ It is easy to seem the limit's existence.  But I don't know how to calculate its value.


How to get return prices for a one way ticket?

I am emigrating to the USA from the UK and need to purchase a flight. I have noticed that direct one way flights are over £1000 and return flights are only just over £500. Is there any way to get the price for a return ticket for a one way? If not, are there any repercussions for not using the return flight? I have a visa and everything is above board, I just don't want to spend the £500 extra when I can just buy a return for half the price of a direct one way.


Providing command key-value arguments with commas in value

When using commands that allow using key-value pairs, how can one provide an argument value that has commas in it? As an example, say I'm using the \newacronym command from the glossaries package as below:  \newacronym[firstplural = Alphas, Bravos, and Charlies (ABCs), plural = ABCs]{ABC}{ABC}{Alpha, Bravo, Charlie}   Unfortunately, the comma is used to separate key-value pairs so the Bravos, and Charlies (ABCs) portion doesn't get parsed correctly. Is there a way to overcome this?


Prove that $\sqrt{a_1} + \sqrt{a_2} +\cdots+ \sqrt{a_n}$ is irrational

$\sqrt{a_1}, \sqrt{a_2} ,\cdots, \sqrt{a_n}$ are irrationals and $a_1,a_2,\cdots,a_n$ are integers $>1$. I didn't find any proof for this exercise. Please help!!


Limit points of the set $\{\frac {\varphi(n) }n : n\in \mathbb{N}\}$

Let $\varphi(n)$ denotes the cardinality of the set $\{a | 1\le a\le n, (a,n)=1\}$ where $(a , n)$ denotes the gcd of $a$ and $n$. Which of the following is NOT true ? $(a)$ There exist infinitely many $n$ such that $\varphi (n)\gt \varphi(n+1)$ $(b)$ There exist infinitely many $n$ such that $\varphi (n)\lt \varphi(n+1)$ $(c)$ There exist $N\in \mathbb{N}$ such that $N\gt 2$ and for all $n\gt N$,  $\varphi (N)\lt \varphi(n)$ $(d)$ The set $\{ \frac {\varphi (n)}{n} : n\in \mathbb{N} \} $ has finitely many limit points.  My Thinking: $(a)$ is true  by selecting $n=p$  ( an odd prime greater than $3$) Justification: Since $p$ is odd, $p+1$ is even. Now $\varphi(p)=p-1$ and $\varphi(p+1)\le p+1-\frac{p+1}{2}=\frac{p+1}2$ So $\varphi(p+1)\le \frac{p+1}2 \lt p-1=\varphi(p)$ By the infinitudes of primes, the result follows. $(b)$ Is true by taking $n=p-1$ where $p$ is an odd prime greater than $3$ and following the same line of reasoning. $(c)$ This statement (if true ) means that the set $\{\varphi(n) : n\gt N\}$ is bounded below. I think it is true My argument : Let $N=6$ . Then $\varphi(6)=2$ If $n\gt 6$ and is prime  , then clearly $\varphi(n)\gt 2$ Otherwise, if $n$ is composite, then let $n=p_1^{r_1} p_2^{r_2}...p_k^{r_k}$ . $\varphi(n)=p_1^{r_1-1}p_2^{r_2-1}...p_k^{r_k-1}(p_1-1)(p_2-1)..(p_k-1)$ If $\phi(n)=2$ , then the distinct primes can be just $2$ and $3$. So the above equality reduces to $2=\phi(n)=2^{r_1}3^{r_2-1}$  when both the factors $2$ and $3$ are present . This gives $r_1=r_2=1$ and so $n=6$ When only $3$ present ,  then we get $n=3$ and if the factor is only $2$ , then $n=4$. So the result follows as $N=6$ works $(d)$ This is NOT true. Justification :- Let $\{p_i\}$ be the enumeration of primes. Let an index $k$ be fixed and $i$ be the running index. Then if the only prime factors of  $n_i$ are $p_k, p_i$ , then $\frac{\varphi(n_i)}{n_i}=\big( 1-1/p_k\big)\big(1-1/p_i\big)$ So ,letting $i\to \infty$, we have $\lim_{i\to \infty}\frac{\varphi(n_i)}{n_i}=1-1/{p_k}$ Since $p_k$ is arbitrary, there are infinitely many limit points (maybe uncountably many) limits points of the given set. Please check if my work is correct or the answers can be shortened in any way. Thanks for your time.


Newton's second law says $F=ma$. Now if we put $F=0$ we get $a=0$ which is Newton's first law. So why do we need Newton's first law ?   Before asking I did some searching and I got this: Newtons first law is necessary to define inertial reference frame on which the second law can be applied.  But why can't we just use Newton's second law to define an inertial frame? So if $F=0$ but $a$ is not equal to 0 (or vice versa), the frame is non-inertial.  One can say (can one?) we cannot apply the second law to define a reference frame because it is only applicable to inertial frames. Thus unless we know in advance that a frame is inertial, we can't apply the second law.  But then why this is not the problem for the first law?  We don't need to know it in advance about the frame of reference to apply the first law. Because we take the first law as definition of an inertial reference frame.  Similarly if we take the second law as the definition of an inertial frame, it should not be necessary to know whether the frame is inertial or not to apply the second law (to check that the frame is inertial).


Adobe Flash Player Issue In Chromium In Ubuntu

Playing Youtube videos in chromium I got the following issue        Flash play is already installed on the system. How do I fix it ?


How to correctly write "A series of tests IS performed" or "A series of tests ARE performed". My thinking is that the verb "performed" is related to the noun "a series", which is singular, because it has "a" in front of it. However If I google (for instance  ) I see that both scenarios are used.


I have a digital ocean droplet with 1 core 2 gigabytes of RAM. Currently the server uses maybe 10 to 20% of the ram. Is running MySQl, redis, failto ban, exim, dovcot, phpmyadmin, roundcube, nginx reverse proxy and some other stuff. Below is the default settings that it has. I would appreciate any advice on what people think would be the appropriate settings for below on this Droplet. Thank you mpm_prefork_module StartServers 8 MinSpareServers 5 MaxSpareServers 20 ServerLimit 256 MaxClients 200 MaxRequestsPerChild 4000 mpm_event_module StartServers 2 MinSpareThreads 25 MaxSpareThreads 75 ThreadLimit 64 ThreadsPerChild 25 MaxClients 200 MaxRequestsPerChild 4000


I have abstractly thought of Pure Linux as a just Linux which has only basic functions.  What is the exact definition of Pure Linux?  How far is it different from Ubuntu or something ?  How can I download the Pure Linux image?(I want to install it on virtual machine)


Does voting to close as duplicate erase earlier comments?

Possible Duplicate:             The first comment on the following question pointed out a previous question and declared that is was similar but not a duplicate.    I responded to the comment, and shortly thereafter the question was closed with a completely different link as a duplicate.  The first comment disappeared, and I thought it was because the owner had deleted it. Later they claim they had not deleted it, so I suspect a bug in the process that closes a question as a duplicate.


I am looking for a way to compress jpeg images on a Mac from Terminal. Basically, a library like pngquant, except it is for jpeg format.  Are you aware of a software that does that?


directory says it is group writable but I cannot write a file within it

I have a group called service in /etc/group that has user webserver as a member.   I am trying to write to a file in /home/service using user webserver. I have a script that confirms that user webserver has write permission to /home/service, yet when I want to write to /home/service/entries_for_processing, then I get a permission denied error, even though both /home/service, and /home/service/entries_for_processing are writable by group service.  What don't I understand about group permissions that it denies me permission to write to /home/service/entries_for_processing as a member of service group?  Below are the permissions of /home/service and /home/service/entries_for_processing:  # file: home/service/entries_for_processing # owner: service # group: service user::rw- group::rw- other::---  # file: home/service/ # owner: service # group: service user::rwx group::-w- other::---   By the way, the script I mentioned that confirms that user webserver can write to /home/service, also strangely confirms that webserver cannot write to /home/service/entries_for_processing nor to any other file I try to open or create in /home/service.


Conference/Journal publication author's name (surname)?

I am just wondering if I can legally use a nickname or not to use my official name (Passport name) as the author's name of a conference or a journal publication?   My official name is quite long and I am planning to change it in the future. Is it possible to put the name that I am going to call myself in the future as the author's name?


What are the uses and pitfalls of regression through the origin?

Spuriously high R-squared is one of the pitfalls of regression through the origin (i.e. zero-intercept models). If the predictors do not contain zeroes, then is it an extrapolation? What are the uses and other pitfalls of regression through the origin? Are there any peer-reviewed articles?


So I entered this and it says this all the time      Data Tag Parsing Failed: Encountered Multiple Top Tags, Only One Expected   And here is the command:   /summon Villager ~ ~1 ~ {NoAI:1,Rotation:[45.0f,-15.0f]},{CustomName:"Fire"}


How to watch live youtube stream using vlc?

Is it possible for now to watch live youtube video streams using vlc? I just don't want to use flash player. I know that vlc can play youtube videos using link for the page where that video is located, but how about live youtube videos?


I have a voltage divisor to measure the voltage of my battery which serves as a battery level detector and it is connected to a GPIO pin in a microcontroller which does not have an ADC. Is it possible to obtain the analog value? And if not is there another way to obtain the value without an ADC?  I have seen a way that will compare the voltage of the Vref of my microcontroller. Is it possible this way?  For the MCU, im using a STM32WB55CGU6 and the pin used is the PB6 (pin 46)


I hate touching the mouse, is there a way to navigate through Stack Overflow questions without doing so?  I'm thinking something akin to Google's search results (not sure how long this has been a feature of theirs).  Once your at the google homepage, you can type your query then navigate the results using up/down arrow to select which result, then hit enter to go to that link.  Something like that would be cool, IMO.


How do I find using the Squeeze theorem  $$\lim_{n\to \infty}\sum_{k=1}^n \frac{1}{\sqrt{n^2+k}} \;,$$  using the fact that  $$ \lim_{n\to \infty}\frac{n}{\sqrt{n^2+n}}=1.$$  Thank you very much for your help,   C.G


Let's say there is the following classes:  class A {     // some data here (let's say - 200 bytes) public:      void foo(); };  class B {     // some data (150 bytes) public:     void bar(); }   And code:  A *a = new A(); a->foo();  B *b = reinterpret_cast<B*>(a); // then we just stop using a a = nullptr;      // and start using this memory as b b->bar();   Is there an undefined behaviour? (If nowhere else in the code a is no longer used, and I'm sure that 150 first bytes of this memory is quite valid for object b).  All i can find is . And how can I understand, what I'm doing is an undefined behaviour...  Of course, I understand that there may be a loss when deleting such a piece of memory using delete b;. But can I use this code, or b->bar() is anyway UB?


Ok so i used virtualbox in windows and ran linux,i accidentally gave it 64gbs. when i realized that it was dumb i uninstalled virtualbox and deleted the folder but i sill didnt get the 64 gbs back. I've already tried searching for the .vdi file but i couldn't find it. Can anybody tell me what to i have to do to get my 64 gbs back? I've already asked these questions in reddit but nobody answered. Need help!


Looking for 1960s YA book about portal to parallel universe

I read a 1960s YA/Juvenile novel about a team of scientists working on a portal to another dimension/universe, looking through the portal drives anyone insane. Can't recall author or title, read it in the early 70s, in a school library hardcover binding. I assume from the style it was a 1960s work, it is possible it was from 1950s.


Which of the two sentences is correct?  Everybody who we need or Everybody whom we need  Please explain the grammatical reason behind it.  Thanks


Macro defining macro defining global macro (similar to `\author` or `\title` fields)

I have already seen these posts  and  but unfortunately I didn't manege to figure it out how to correct my attempt to the problem. I want to create a macro which will produce macro + global macro with @ in front of macro name, like in the following example:   \def\Bob#1{\gdef\@Bob{#1}}  \Bob{My name is Bob}  \makeatletter  \@Bob % it will display `My name is Bob'  \Bob{Name: Bob}  \@Bob % it will display `Name: Bob'  \makeatother   So this works. However:   \def\DefineField#1{%      \expandafter\edef\csname #1\endcsname##1{%          \gdef\csname @#1 \endcsname{##1}%      }%  }  \DefineField{Alice}  \Alice{My name is Alice}   doesn't work. I got Undefined control sequence. with \@Alice. I have checked Alice and Bob with \show command:  > \Bob=macro: #1->\gdef \@Bob {#1}. l.20 \show\Bob > \Alice=macro: #1->\gdef \@Alice  {#1}. l.21 \show\Alice   They have exactly the same structure. What did I miss? MWE:  \documentclass[preview]{standalone} \makeatletter  \def\DefineField#1{%     \expandafter\edef\csname #1\endcsname##1{%         \gdef\csname @#1 \endcsname{##1}%     }% } \DefineField{Alice} \Alice{My name is Alice}   \def\Bob#1{\gdef\@Bob{#1}} \Bob{My name is Bob}  \begin{document} %\@Alice  % Undefined control sequence. \@Bob \Bob{No my name is Alice}  \@Bob \show\Bob \show\Alice \makeatother \end{document}


SQL Server - Login failed. The login is from an untrusted domain and cannot be used with Windows authentication

I am getting below error while trying to connect SQL from remote server. Local login is working fine. Can anyone help on this. Thanks in advance. "Login failed. The login is from an untrusted domain and cannot be used with Windows authentication. [CLIENT: 10.186.12.10]" My environment : Client - already test AD/DNS domain joined Remote SQL Server - already prod AD/DNS domain joined I have running inside test AD/DNS server isolated environment. No relationship between test AD/DNS server and prod AD/DNS server. Test domain name : contoso.com Otherwise , PROD domain name : contoso.com Test AD/DNS Server : 10.190.10.1 Prod AD/DNS Server : 10.150.10.1 Do I have to join prod AD/DNS client machine as well ? I mean , is there any workaround solution ? Thanks in advance, Last Update: Solved my issue.


Is there a bijective map from $\mathbb{R}$ to ${}^{*}\mathbb{R}$?

Is there a one-to-one correspondance between the real numbers and the hyperreal numbers?


Points of discontinuity of a bijective function $f:\mathbb{R} \to [0,\infty)$

We know that the points of discontinuity of a monotone function on an interval $[a,b]$ are countable. Using this can we prov that:    Any bijection $f: \mathbb{R} \to [0,\infty)$ has infinitely many points of discontinuity.   If yes, how or otherwise how to prove the above result?


L293D (Motor Driver sheild. ) Overheating issue

I really do have a doubt. Actually I'm making Vplotter and for that I'm using 333nNm 0.31 A Stepper motor NEMA 17. And I'm giving an external supply of 5V and 1 A to motor driver sheild. Will L293D heat.


Species Identification : Worm like insect but broad at back

Can anyone help me identify this insect  Location: Southern India  Size: About 2cm  It looks like a worm but has a broad back, it seems like (not very sure) it tucks it's thin head inside the broad shell like body to ward off.  Here is the picture,


Stack Overflow, Stack Exchange, Area 51: What's the difference in a nutshell? I've read the faq's and they all seem to be the same to me - Just Q & A on a variety of topics.  What's the difference in a nutshell? If I have a software engineering question, which site is best for me to use?


Traversing through Linked List throws me a Null Pointer exception

In a double ended Linked List, , I used another Link theLink which is copied through copy constructor to copy firstLink . But when I iterate through Linked List to insert from the back end , It throws me a Null Pointer Exception.  package javaapplication2;  import java.util.Arrays;  public class DoubleEndedLinkList {  Link firstLink; Link lastLink; int data;   public boolean isEmpty() {     return firstLink == null; }  public void insertAbove(int data) {     Link toInsert = new Link(data);      if (isEmpty()) {         firstLink = toInsert;     } else {        // System.out.println("firstLink : " + firstLink.data);         toInsert.next = firstLink;         firstLink = toInsert;     } }  public void insertBelow(int data) {    Link toInsert = new Link(data);    if(isEmpty()){        lastLink = toInsert;    }else{        Link traversal = new Link(firstLink);        while(traversal!=null){            traversal = traversal.next;        }        System.out.println("LastLink = " + traversal.data ); //Here exception occurs         lastLink = traversal;        lastLink.next = toInsert;        lastLink = toInsert;    } }  public void display() {     Link theLink = firstLink;     try {         System.out.print(theLink.data + "->");         theLink = theLink.next;         while (theLink != null) {             System.out.print(theLink.data + "->");             theLink = theLink.next;         }         System.out.print("||");      } catch (NullPointerException e) {         System.out.print("->||");     }  }    @Override public String toString() {     return String.valueOf(data); }   public static void main(String[] args) {      DoubleEndedLinkList dl = new DoubleEndedLinkList();     dl.insertAbove(5);     dl.insertAbove(10);     dl.insertAbove(15);     dl.display();     dl.insertBelow(99);     System.out.println("FirstLink = " + dl.firstLink.data + " LastLink = " + dl.lastLink.data);   }   }


Ubuntu 14.04 - User desktop launcher is missing

The same question has been asked before, but the answers that I found did not work for me, so I'm asking a new question.  I'm the main user and only sudoer on this computer, and everything works for me.  The second user account on this machine for no reason that I can think of, no longer displays the launcher sidebar or top bar, neither does CTRL + ALT + T work. Icons are normally displayed on the desktop (in most other related questions like this the desktop is blank).  So I've found and tried so far:   rebooting sudo service lightdm restart unity --replace unity --reset-icons apt-get install --reinstall ubuntu-desktop apt-get install --reinstall lightdm remove files under /home/USER/.config/compiz-1/compizconfig starting ccsm from tty to enable unity plugin   unity reset commands return "no display variable set" and "compiz core couldn't open display 0".  When I try to launch unity from tty with DISPLAY=:0 unity I get the following:  Invalid MIT-MAGIC-COOKIE-1 keycompiz (core) - Fatal: couldn't open display :0   Which sounds like it could be relevant?  How to restore desktop panels?


First time home buyer: How to begin shopping for a home mortgage loan?

I am completely new to the world of mortgages and home loan lending, and I am looking to buy a new house. I am either looking to take out a traditional mortgage or a home equity loan on a house that I own with my parents (which has been mostly paid off now).  I really have no idea how to begin this process. I got some  , but I am still not clear on how to start shopping around for the best loan.  Should I go to my local bank and speak to someone there, or lendingtree.com, or hire a realtor?  (Please do not consider this question subjective, I am just looking for advice and not necessarily the "right" answer).


Does CPU temperature affect CPU lifespan?

As long as a CPU's temperature stays below the manufacture-specified maximum, does a CPU's average temperature affect its lifespan?  For example, my laptop's maximum CPU temperature as specified by Intel is 100(C). If I run it at 90(C) for a period of time vs. running it at 40(C) for the same period of time, will there be a difference in how much of the processor's life that has been used up?  Is there credible scientific research on this subject?  My reason for asking this is that I am trying to determine whether to increase my default fan speeds in order to lower the temperature that my CPU idles and works under light load such as typing this question.  P.S: even though I've tagged this 'overclocking', this question is not concerned with the effects of overvolting a CPU.


How to update jquery version without hacking or updating the core?

I am trying to upgrade my the core/jquery library from 3.2 to 3.4.1 in the core. How can I update the assets/vendor/jquery/jquery.min.js defined in core.libraries.yml to a further jquery version? I can not currently update my drupal to v8.9, which comes with v3.5 of jQuery. I am using drupal 8.6 So far I have tried looking at  but the recommended module doesn't seem to be available for drupal 8 and above.


so I wanted to install a dock bar called "docky". It, didn't work because I had to do the command sudo apt-get update but I get this output:  Hit:2 http://lu.archive.ubuntu.com/ubuntu disco InRelease                       Hit:3 http://linux.teamviewer.com/deb stable InRelease                          Hit:4 http://lu.archive.ubuntu.com/ubuntu disco-updates InRelease    Hit:5 http://security.ubuntu.com/ubuntu disco-security InRelease     Hit:6 http://lu.archive.ubuntu.com/ubuntu disco-backports InRelease Ign:7 http://download.virtualbox.org/virtualbox/debian 19.04 InRelease Get:8 http://download.virtualbox.org/virtualbox/debian disco InRelease [4.428 B] Err:8 http://download.virtualbox.org/virtualbox/debian disco InRelease  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A2F683C52980AECF Err:9 http://download.virtualbox.org/virtualbox/debian 19.04 Release  404  Not Found [IP: 92.122.252.21 80] Reading package lists... Done W: GPG error: http://download.virtualbox.org/virtualbox/debian disco InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A2F683C52980AECF E: The repository 'http://download.virtualbox.org/virtualbox/debian disco InRelease' is not signed. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details. E: The repository 'http://download.virtualbox.org/virtualbox/debian 19.04 Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.   I don't know how to fix this. Did anyone have the same issue?


Securely Storing a static API secret/key in a Salesforce app

I recently submitted an application to the AppExchange, only to have it not pass the security check due to "Insecure Storage of Sensitive Data Vulnerability." The problem is that my app accesses an external API, for which it has its own API Secret and API Key. These are static, and specific to the Salesforce App- they will be the same for all users, all installations, etc.  Perhaps stupidly, I stored them as private properties of the class that uses them.  private static String apiSecret = 'superS3|<R37'; private static String apiKey = 'sameHerebutdifferent';   It is a Managed app, so users cannot see them. As such, I am puzzled as to 1. why this is insecure and 2. how better to store these values, given that we are apparently operating under the assumption that having them in the text of the class itself is insecure.


Err:39 + getdeb while upgrading and updating

I get this problem when doing sudo apt-get update && upgrade on Ubuntu 16.04:  Err:39 http://archive.getdeb.net/ubuntu xenial-getdeb InRelease Could not connect to archive.getdeb.net:80 (144.76.200.19), connection timed outFetched 4,750 kB in 2min 0s (39.5 kB/s) AppStream cache update completed, but some metadata was ignored due to errors. Reading package lists... Done W: Failed to fetch http://archive.getdeb.net/ubuntu/dists/xenial-getdeb/InRelease Could not connect to archive.getdeb.net:80 (144.76.200.19), connection timed out W: Some index files failed to download. They have been ignored, or old ones used instead.   How can I fix this?


On clicking an acronym, go to the first instance, not the table of acronyms

I am using the glossaries package together with hyperref, but I realize that I don't need the table of acronyms. Rather, I would prefer that on clicking an acronym, I want to reach the first instance of \gls{myacronym}. Is there anyway to do that.  Thank you  Edit: Added sample code  \documentclass[11pt]{article} \usepackage[a4paper, total={6.5 in, 9.5in}]{geometry} \usepackage{hyperref} \usepackage[acronym]{glossaries}  \newacronym{acr}{myacr}{My Acronym}  \makeglossaries \begin{document} \section{Introduction}  I refer to the acronym here \acrfull{acr}. Since, I don't have a list of acryonyms, on clicking the acronym link I want to go to the section where the acronym is explained.  \pagebreak  \section{Chapter on My Acronym} \gls{acr} is explained here in detail. On clicking an occurrence, the reader should be directed here. \end{document}    Edit 2: Some users have marked this question as a duplicate, but it's not. My question is that any occurrence of an acronym should link to it's first occurrence, rather than the list of acronyms. In contrast, the "other" question asks about linking the first occurrence with the list of acronyms.


Alternative to VSS for a one man show (army of one?)

I've been programming for 10+ years now for the same employer and only source code control we've ever used is VSS. (Sorry - That's what they had when I started). There's only ever been a few of us; two right now and we usually work alone, so VSS has worked ok for us. So, I have two questions: 1) Should we switch to something else like subversion, git, TFS, etc what exactly and why (please)? 2) Am I beyond all hope and destined to eternal damnation because VSS has corrupted me (as Jeff says) ?  Wow - thanks for all the great responses!   It sounds like I should clearify a few things. We are a MS shop (Gold parntner) and we mostly do VB, ASP.NET, SQL Server, sharepoint & Biztalk work. I have CS degree so I've done x86 assembly C, C++ on DEC Unix and Slackware Linux in a "time out of mind" ...         My concern with VSS is that now I'm working over a VPN a lot more and VSS's performance sux and I'm afraid that our 10+ y/o version 5 VSS database is going to get hoosed... There's the LAN service that's supposed to speed things up, but Ive never used it and I'm not sure it helps with corruption - has anyone used the VSS LAN service? (new with VSS 2005)


How exactly do I tell if "A xxx of" is plural or singular?

I looked up a few grammar-teaching websites (in Chinese language). The website says many people do not use the phrase "A xxx of" correctly because they do not identify the subject of the phrase correctly.   The website says phrases like "A range of; A high percentage of" is singular, while "a number of; a group of; a couple of; a total of" is plural.  Therefore according to the website, the correct sentences should be as follows.     A wide range of courses is available. ("A wide range" is the subject)      A high percentage of peptides that are made of amino acids is present   in the sample. ("A high percentage" is the subject)      A number/ group/ couple of people were killed in the earthquake.("people" is the subject )       A total of 230 employees were laid off. ("employees" is the subject)   I don't get the pattern here. All of this looks (or should I use "look"?) arbitrary to me. In fact I thought this phrase is supposed to be arbitrary and whether the phrase is plural or singular should depend on the the person's own judgment.   How do I identify the correct subject in the "A xxx of" phrase?


I was solving the integral $$\int_{-\frac{\pi}{2}}^{\frac{\pi}{2}}\frac{1}{\tan^6(x)+1}dx$$ and here's my solution:  Let $I = \int_{-\frac{\pi}{2}}^{\frac{\pi}{2}}\frac{1}{\tan^6(x)+1}dx$, then $$I=2\int_{0}^{\frac{\pi}{2}}\frac{1}{\tan^6(x)+1}dx.$$ Subs. $u=\tan x,dx=\frac{1}{1+u^2}du$.  $$I = 2\int_{0}^{\infty}\frac{1}{(1+u^6)(1+u^2)}du$$ $$I=2\left(\int_{0}^{1}\frac{1}{(1+u^6)(1+u^2)}du +  \int_{1}^{\infty}\frac{1}{(1+u^6)(1+u^2)}du\right).$$  On the first integral, $u \mapsto u^{-1}$, ending with $$I=2\int_{1}^{\infty}\frac{du}{1+u^2}=\frac{\pi}{2}.$$  Using the same approach, I was able to prove that the equality holds for all $n\in \mathbb{Z}$. Going beyond, and using Wolfram Alpha, the equality seems to hold for all reals $n$, but only for the real part. So, here's my question:      Claim. Let $$\mathcal{I}=\Re{\int_{-\frac{\pi}{2}}^{\frac{\pi}{2}}\frac{1}{\tan^{2n}(x)+1}dx}.$$ Then, $\mathcal{I}=\frac{\pi}{2}, \forall n \in \mathbb{R}.$   First of all: Is the Claim true?  If positive, can I prove it using the same methods?


If a ring has a left identity that is not a right identity, then there must be more than one left identity

For a ring $R$, I must show that if R has a left identity that is not a right identity, then there is more than one left identity.   Could I do this by contradiction, using 2x2 matrices and show that a given set has two left identities that are not right identities?


Please add the list of questions (un-)protected to the profile page

Currently, the profile page does not show which questions one (un-)protected.  One  (at most one week old, not containing deleted questions), but that's somewhat cumbersome. I guess it should be the point eight under the votes tab, not number nine under the actions tab, though it doesn't matter that much.


I'm getting an error - didnt understand relationship when running this query in dev console. I have set the child relationship the lookup field to IncEvents. The lookup field is on the MyRule object -   select Id, Name, (select Id from IncEvents_r) from Namespace_MyRule__c  I noticed that the editor is displaying a single underscore between the namespace and the object name but I did enter a double underscore.


Why were wayfinder directions written on a dagger?

In The Rise of Skywalker, the heroes find the location of a Sith wayfinder by reading a runic inscription on Ochi's dagger.  What purpose does it serve to inscribe a random artifact's location on an unrelated tool? Was there some sort of relationship between the dagger and the wayfinders that I missed?


Cannot Connect to Wireless Wifi version 17.04 (no available networks shown)

This may seem like a duplicate question, but I have spent hours searching through the Ubuntu and StackExchange forums looking for an answer and cannot find anything that works.  Yesterday, I downloaded Ubuntu 17.04.  The first thing I did was to attempt to connect the OS to the internet.  I went to Network settings, and discovered that I had two options: Wired or Network Proxy (I can also add a VPN).  There was nothing in the menu bar other than the 'Help' option; there also weren't any other extended options besides those under Wired or Network Proxy (which is why the Ubuntu wireless troubleshoot page isn't helping).  I have checked, and I do have the following Network controller: Broadcom Limited BCM43142 802.11b/g/n (rev 01)  I looked under Additional Drivers and found that it says that the OS is running the driver; specifically "Using Broadcom 802.11 Linus STA wireless driver source from bcmwl-kernel-source (open source)".  However, no matter what I do, I cannot see or find the wireless network I need to connect to.  This computer is a Dell, only about 2 years old, and the original OS is Windows 10.  Your help is very much appreciated.  Thanks!


Travelling from USA to Canada and return

I have an esta.  I am flying into USA, staying overnight before travelling to Canada by land arriving in Canada 12 hours later. I will be in Canada 100 days. Will I be able to return by land to USA to allow me to fly home?


Is there a way to convert a .JPG image in to vector format?  I'm using Illustrator and I've tried that "Image Trace" but the result doesn't look any where close to my original.  Plus, I cannot select individual letters of a word like I can in an .AI or .EPS file.


Getting rid of youtube.com's recommended videos/channels

Every time I navigate to youtube.com it recommends videos and channels that I might be interested in or want to see. I just don't want that annoying stuff to appear and distract me from my actual intentions.  I searched the web the last two days using different wordings and buzz words and got a number of approaches to get rid of those 'recommended xyz' sections, but none helped me out.  All techniques had one thing in common: A mechanism that would allow youtube.com to remember me (and the appropriate way to disable this feature):   YouTube/Google-Account (with search history) Browser Cookies Browser Cache   The weird thing is, I don't use any of these. I am not logged in to a user account and I am clearing the cookies and the cache every time my browser closes (I use Firefox).  Here is what I have tried so far:   Activated the history settings to enable cookies and history to be stored (that was the only way enable the corresponding "delete" buttons) and deleted them manually Tried different browsers Tried different computers (and smartphones!) in my home network Changed my (external) IP address (by resetting my router's internet connection), multiple times   None of these things helped. YouTube.com seems to remember me every single time no matter what browser or PC I use or what IP from I connect.  Is there any thing I've missed? How does YouTube remember "me"? I am using quotation marks because "me" could be anyone using my internet connection (family, friends, etc.). And because of that I don't want a solution that involves installing custom 'blocker' or 'remover' software.


Removing multiple files from a Git repo that have already been deleted from disk

I have a Git repo that I have deleted four files from using rm (not git rm), and my Git status looks like this:  #    deleted:    file1.txt #    deleted:    file2.txt #    deleted:    file3.txt #    deleted:    file4.txt   How do I remove these files from Git without having to manually go through and add each file like this:  git rm file1 file2 file3 file4   Ideally, I'm looking for something that works in the same way that git add . does, if that's possible.


Run each Virtual Machine as a separate application

I am currently running Ubuntu 14.04 with VirtualBox installed. I have a Windows 10 VM installed and a Kali VM as well. When they boot, they both come up as windows of the VirtualBox program, like so:  But I would like it to look like Windows and Kali are separate "apps" installed on the system. So when each one is open, they will have their own icon in the launcher, with the Windows and Kali logo respectively. I have tried this by making 2 .desktop files and dragging them to the launcher and then clicking on them, but that just opens the VM under a separate VirtualBox icon, just as is shown on the screenshot above.


How to migrate an Community with audience

Thank for reading the post. I have lots of Audience to assign in my community/experience builder. Is there any ways to migrate Audience , community and the assignment of audience and community component.


What happens when a photon hits a mirror?

When a photon of light hits a mirror does the exact same photon of light bounce back or is it absorbed then one with the same properties emitted? If the same one is bounced back does it's velocity take all values on $[-c,c]$ or does it just jump from $c$ to $-c$ when it hits the mirror?  Or, is the phenomenon of a mirror better explained using a wave analogy? If so, what is this explanation?


Can I use a flicker effect to stop an opponents blocker from blocking

Pretty much what the title says. Supposing I have the ability to flicker an opposing blocker, can I force damage past it?  To give a concrete example:  Suppose my opponent has:   1 untapped vanilla creature on the battlefield 1 life No lands on the battlefield No cards in hand. 1 Enchantment saying, "In your upkeep, you win the game".   And I have:   1 haste-y creature on the battlefield Flicker of Fate in hand (flicker and creature, for 1 white + 1 generic). Two untapped plains on the battlefield   It's my first main phase.  Can I use flicker to prevent their blocker from blocking and win the game?  If so, exactly what is the timing?


I need to wrote the follwing task that will be part in my bash script  we want to match all lines with UUID words in fstab file according to the following rules:  UUID is in begging of file or beginning after space or spaces or tab  example  UUID="61e9e16f-eb49-4c97-aaf0-0ed2dc3f3007"       UUID="61e9e16f-eb49-4c97-aaf0-0ed2dc3f3007"     UUID="61e9e16f-eb49-4c97-aaf0-0ed2dc3f3007"   second it will not match on the following cases  if UUID is begin after comment "#" or UUID isnt in the beging of file  example  #UUID="61e9e16f-eb49-4c97-aaf0-0ed2dc3f3007"  "61e9e16f-eb49-4c97-aaf0-0ed2dc3f3007" UUID #      UUID="61e9e16f-eb49-4c97-aaf0-0ed2dc3f3007"


How can I keep a command I started from the shell running if I logout from the shell?

Which methods exist to keep a command that was started from shell on running after logging out from from shell?


Java: "exception in thread main java.lang.nullpointerexception"

I am getting an the java.lang.nullpointerexception error in my code. Though I am not sure why it is not correct. I should be a quick fix, but I can't seem to figure it out. It seems that the array in line 45 is giving me the error. Any help would be greatly appreciated. Thank you in advance.  import java.io.File; import java.io.FileNotFoundException; import java.util.Scanner;  class readFile {     private String fileName;     private double lowestNum;     private double highestNum;     private double totalNum;     private double averageNum;     private int[] array;      public readFile(String input)     {         fileName = input;         lowestNum = 0;         highestNum = 0;         totalNum = 0;         averageNum = 0;     }      public void readArray() throws FileNotFoundException     {         Scanner s = new Scanner(new File(fileName));         array = new int[s.nextInt()];         for(int i = 0; i < array.length; i++)         {             array[i] = s.nextInt();         }         s.close();     }     \\ERROR IS HERE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!     public void findLowest()     {         lowestNum = array[0];         for(int i = 1; i < array.length; i++)         {             if(array[i] < lowestNum);             lowestNum = array[i];         }         System.out.println("Lowest number: " + lowestNum);     }      public void findHighest()     {         highestNum = array[0];         for(int i = 1; i < array.length; i++)         {             if(array[i] > highestNum);             highestNum = array[i];         }         System.out.println("Highest number: " + highestNum);     }      public void findTotalNum()     {         for(int i = 0; i < array.length; i++)         {             totalNum = totalNum + array[i];         }         System.out.println("Total of all numbers: " + totalNum);     }      public void findAverage()     {         averageNum = (totalNum / array.length);         System.out.println("Average of all numbers: " + averageNum);     } }  public class NumberAnalysis  {     public static void main(String[] args) throws FileNotFoundException      {         String fileName = "Numbers.txt";          readFile myClass = new readFile(fileName);         myClass.findLowest();         myClass.findHighest();         myClass.findTotalNum();         myClass.findAverage();     } }


How to calculate limit of sequence : $a_n=\frac{1^k+2^k+3^k+...+n^k}{n^{k+1}}$?

Let $$a_n=\frac{1^k+2^k+3^k+...+n^k}{n^{k+1}}$$  I need to find $$\lim _{n\to \infty }\left(a_n\right)$$  I know that   $a_n=\frac{1^k+2^k+3^k+...+n^k}{n^{k+1}}=\frac{1}{n}\left(\frac{1^k}{n^k}+\frac{2^k}{n^k}+\frac{3^k}{n^k}+...+\frac{n^k}{n^k}\right)=\sum _{i=1}^n\:\frac{i^k}{n^k}\cdot \frac{1}{n}$  how can i continue from here ?  thanks


What are the trailing number of the zeroes in the given integer

Problem Statement:- The number of zeroes at the end of the integer   $$100!-101!+\ldots-109!+110!$$   I am having a bit of a trouble in thinking how do I proceed. A little push in the right direction would be appreciated.   And if you are posting a full solution do use the spoiler tag, as sometimes I cant stop myself from seeing the whole solution and lose the chance of thinking through it by myself with a push in the right direction from you guys.  Also, I dont know whether I am using the right tag feel free to correct it if its wrong.


program stopping due java.lang.NullPointerException: Attempt to invoke virtual method

My app is getting crashed due this error        Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference   Now I know this is caused by some null reference but I'm Not able to figure it out, here's where exactly the problem happen, after pressing the alert key   beforeGenerate.setPositiveButton("Confirm", new DialogInterface.OnClickListener() {         @Override         public void onClick(DialogInterface dialog, int which) {  //------------------- This code is for generating the qr image----------------------              String studentId = String.valueOf(takeText.getText());             int dimension = 200;             QRCodeEncoder qrCodeEncoder = new QRCodeEncoder(studentId, null, Contents.Type.TEXT,                     BarcodeFormat.QR_CODE.toString(), dimension);     String fileName = "studentID";             try {                 Bitmap bitmap = qrCodeEncoder.encodeAsBitmap();                 ByteArrayOutputStream bytes = new ByteArrayOutputStream();                 bitmap.compress(Bitmap.CompressFormat.JPEG, 100, bytes);                 FileOutputStream fo = openFileOutput(fileName, Context.MODE_PRIVATE);                 fo.write(bytes.toByteArray());                 fo.close(); // going for next activity and show QR             Intent i = new Intent(idEnterActivity.this, showQR.class);             startActivity(i);             } catch (Exception e) {         }         }     });   I'm trying to go to this activity   public class showQR extends ActionBarActivity {  public void onCreate(Bundle savedInstantState){     super.onCreate(savedInstantState);     setContentView(R.layout.activity_show_qr);     Context context = this;     Intent i = getIntent();     String fileName = i.getExtras().getString("fileName");     try {         Bitmap bitmap = BitmapFactory.decodeStream(context                 .openFileInput(fileName));         ImageView gg = (ImageView)findViewById(R.id.qrCode);         gg.setImageBitmap(bitmap);     }     catch(Exception e){      } }   }  this is my manifests file   <?xml version="1.0" encoding="utf-8"?>     <application     android:allowBackup="true"     android:icon="@drawable/ic_launcher"     android:label="@string/app_name"     android:theme="@style/AppTheme" >     <activity         android:name=".splach"         android:label="@string/app_name" >         <intent-filter>             <action android:name="android.intent.action.MAIN" />              <category android:name="android.intent.category.LAUNCHER" />         </intent-filter>     </activity>     <activity         android:name=".Main"         android:label="@string/app_name" >     </activity>     <activity         android:name=".idEnterActivity"         android:label="@string/title_activity_id_entet" >     </activity>      <activity         android:name=".showQR"         android:label="@string/abc_action_bar_home_description">     </activity>  </application>     I'm newbie in programming, so please tell me what I'm messing :)  EDIT  That's the rest of logcat from   Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference         at impresesnt.abedbayoun.impresent.showQR.onCreate(showQR.java:22)         at android.app.Activity.performCreate(Activity.java:5933)         at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)


How does Xavier get the use of his legs back after "X-Men: First Class"?

At the end of First Class, Xavier is paralysed, and him and Magneto split paths. However at the beginning of Last Stand, it flashes back 20 years, and you see the grown up Xavier and Magneto, friends, talking to a young Jean Gray.  Did Xavier get the use of his legs back and then lose it again?  Or is this just a continuity error?


Difference between tensor product and main effects plus interaction in mgcv

I was under the impression that using te and adding the main effects with s plus the interaction with ti is the same (in a GAM model, estimated with mgcv).  However:  library( mgcv ) library( gamair ) data( brains )  tm <- gam(medFPQ~te(Y,X,k=10),data=brain,family=Gamma(link=log)) tm1 <- gam(medFPQ ~ s(Y,k=10,bs="cr") + s(X,bs="cr",k=10) +          ti(X,Y,k=10), data=brain, family=Gamma(link=log))  predict(tm)[955] predict(tm1)[955]   (The example is copied verbatim from Simon Wood's GAM book, page 335, so the specification should be correct.)  So, aren't these two formulations equivalent...?