Newly installed applications not appearing in various LXDE dialogs

I've installed some applications via apt.  Here they are in the LXDE menu (note the two IDEs and also the "Graphics" menu are present):    If I right-click on the Application Launch Bar and select "Application Launch Bar Settings" like so:    The settings dialog does not have any of the applications I've installed (note also, the "Graphics" category is empty - there is no + icon next to it):    The problem isn't limited to the launch bar settings dialog, either.  If I right-click a PNG image in the file browser and select "Open With...", that dialog is also missing the newly-installed applications (note again the absence of the + icon next to the "Graphics" category):    So:  Why are installed applications not appearing in these dialogs, even though they do appear in the main application menu?  Note that they are present in the applications database directory:    Environment:  A fresh install of the latest Raspbian and the PIXEL desktop environment (which is essentially just a reskinned LXDE).    Note for those who think this is a duplicate of :  It isn't.  That other question is asking how to add applications to the launch bar.  I know how to do that.  I am not asking how to do that.  I am asking:  Why is LXDE not showing all of the installed applications in various dialogs which are supposed to list all of the installed applications?


What does the (2) after Unix system calls names mean?

I was looking through some documentations for my university task and noticed that all of the syscalls there are followed by (2), like execv(2), fork(2) or fcntl(2). What do they represent?


In many texts and books about calculus we see     There are functions $f$ for which the anti-derivative cannot be   expressed in terms of standard functions or there are many   integrals that cannot be expressed in terms of standard functions.   What functions are called standard functions and why?


How can I challenge a grade based on false accusation of submitting non-original work?

I need some advice on what I can do, and how much hope is left on this case-  A couple of months back, I finished my Media GCSE and got a C. It's alright, I guess, but I hoped for a little higher. It turns out I got 2 points off a B. What dragged me down was my Horror Movie Trailer Coursework- I had to make a horror movie trailer.  I decided to do mine a bit differently- I made a basic engine in Unity and built a 3D Horror world around it. It was made out of assets made by me, including textures, code and I worked solo on it completely. It turned out great, and it wasn't the trailer itself that my teacher had a problem with. It was the fact that he didn't believe it was mine, and I got under half marks because of this.  The trailer was owned completely by me- I owned the textures, code, I did the editing- everything. But because it was made in Unity and the graphics were pretty well, my teacher wasn't buying that it was mine. There was quite a time frame before me submitting my work and getting the results back. I didn't think this problem would arise, so I deleted my work, and the project is gone due to a change in laptop. Now, I have no evidence of it.  I believe that the coursework was marked unfairly, but with no evidence of the coursework, and as I've already received the C, I'm not sure what I can do about it, but I really badly want that B.  Can I not bring it up with the school? Could I write a complaint letter or something? I just don't know what I can do- I'm a bit lost. I hope you can help me, and sorry if this is the wrong place. I was just disappointed in getting a C when I should have a B.


How can I convert 0-5V to +/-2V using a dual supply op amp?

I have a 0-5 volt variable frequency sine wave signal source I am trying to convert to +/-2V.  I would like to preserve the frequencies 20Hz-20KHz.  I have a +5 and -5 volt signals I would like to use as power supplies.  How can I level shift this signal down 2.5 volts so that it is centered at 0, and amplify the signal by 0.8 using a dual supply op-amp?


The following is Cauchy condensation test:  If $b_n \ge 0$ and $b_n \ge b_{n+1}$ then $\sum b_n$ converges if and only if $\sum 2^n b_{2^n}$ converges.  Is the following modified Cauchy condensation test possible:  Let $N \in \mathbb N$. Then if $b_n \ge 0$ and $b_n \ge b_{n+1}$ then $\sum b_n$ converges if and only if $\sum N^n b_{N^n}$ converges?


Remove password from 2007 word document while actual password doesn't work

How do I remove password protection from a 2007 word document (docx)? When entering the right password I get an error message telling me the password would be wrong. But: I'm definetly sure it is right. I tried several methods like renaming it to *.htm (), *.zip or *.rtf but nothing helped.  Any ideas on solving this problem?


Asking here because I'm having a bear of a time trying to Google this. Is there a name for the structure, often observed in spoken English, in which a sentence begins with a noun phrase followed by a comma and a pronoun that serves as the subject of the sentence, with the antecedent of the pronoun being the preceding noun phrase? It's similar to the way stress pronouns are often used in French (e.g. "Moi, je m'appelle..."). Here's an example of what I'm talking about: "Students with more than one major, they tend to have very little free time." Anyone aware of a consensus on the correctness of this structure in an informal register?


Suppose $X_1, X_2, ..., X_n$ are i.i.d.r.v., where $X_i>0$ and $EX_i=\mu$, $Var(X_i)=\sigma^2$. Find $E\left(\frac{X_1+X_2+...+X_m}{X_1+X_2+...+X_n}\right)$, if $m<n$.  Any ideas how to even start this problem?


When the adverb “however” is used to introduce a contrary statement, does it have to be followed by a comma?  I know in such usage, "however" usually accompanies with a comma, but still I found an exception here:         Is that an accidental error, or the use of "however" without a comma does exist in some nonstandard English?


gained a reputation of painting red the draft dissertations of his students, taking particular note of incidents when they omitted a non-breaking space that should have been included.  I have this list of places where you have to place non-breaking space:   before \cite before \ref before inlined equation   But, I am not sure if I got the rules right; is a non-breaking space mandatory  before all inline equations? How about numbers which occur in the text? And what if I refer to a program variable, or to program text, for example,  The 371 programmers who read, on 11 different occasions, the Java program in Figure~\ref{Program:Example}  noticed that it is peculiar since parameter \texttt{i} is never read by functions \texttt{f()} and \texttt{thisLongFuncgtionName()}...   Do I have to write The 371 programmers or The~371 programmers? on 11 different occasions or on~11 different occasions?  Do I need to write parameter~\texttt{i}? I think I should. What about functions~\texttt{f()}? And should I write and~\texttt{thisLongFuncgtionName()}? How about citations that use author, year convention?  In short, I think have an idea, but no exact definition of when you should add non-breaking space.


Characterization of Topology by Boundary (solved)

Similar to my earlier question I try to understand the characterization of topology by different approaches. There is the "classical" one with open sets, the one with closed sets, the neighborhood characterization and one with closure and interior operator, respectively. (In addition, there is also a possibility to define a topology with respect to filter convergence but I did not dig into that yet. Are there further approaches besides the ones mentioned?). Since $\mathrm{boundary}(A) = \mathrm{closure}(A)\setminus\mathrm{interior}(A)$ it should be possible to characterize a topology by a boundary operator only. My thoughts so far:  Theorem. Suppose that $\mathcal T\subseteq2^X$ is a family of sets and $\partial:2^X\rightarrow 2^X$. Then   $\mathcal T$ is a topology $\partial A := \mathrm{closure}(A)\setminus\mathrm{interior}(A)$   iff   $\partial$ satisfies   $\partial\partial A\subseteq\partial A$, $\partial(A\cup B)\subseteq\partial A\cup\partial B$, $A\subseteq B$ implies $\partial A\subseteq \partial B\cup B$, $\partial A = \partial(X\setminus A)$ and   $\mathcal T = \{U\subseteq\Omega : \partial U\cap U = \emptyset\}$.   I managed to show "$\Rightarrow$". I struggle with the reverse direction however. That $\emptyset,X\in\mathcal T$ is easy. But I could not manage to show the arbitrary unions and finite intersections. My attempt:  Let $A_i\in\mathcal T$ for $i\in I$, $I$ finite. Then  $$\partial\left(\bigcap_{i\in I}A_i\right) \cap \left(\bigcap_{i\in I}A_i\right) \subseteq \left(\bigcap_{i\in I}A_i\right)\cap(\partial A_i\cup A_i)$$ for each $i\in I$ by the third property. But Since $A_i\in\mathcal T$ it follows that $\partial A_i\cap A_i =\emptyset$. So we have $\partial\left(\bigcap_{i\in I}A_i\right) \cap \left(\bigcap_{i\in I}A_i\right) =\emptyset$. Is this correct?  Let $A_i\in\mathcal T$ now for all $i\in I$ with arbitrary $I$. Then $\emptyset = A_i\cap\partial A_i$ for all $i$ by assumption. Thus, $$\begin{align*}\emptyset &= \bigcup_{i\in I}(A_i\cap\partial A_i)\\&=\bigcup_{i\in I}(A_i\cap\partial A_i)\cap\partial\left(\bigcup_{i\in I}A_i\right)\\&\supseteq\bigcup_{i\in I}A_i\cap\partial\left(\bigcup_{i\in I}A_i\right)\end{align*}$$ because intersection with emptyset is emptyset. So, $\bigcup_{i\in I}A_i\in\mathcal T$.  Note In the other questions for which my question was flagged as duplicate answer this questions by showing that there exists a one-to-one relation between boundary and closure. I however wanted to prove that boundary characterizes a topology straight.


currently writing up my report for my uni project and I am unsure if I can accept my hypothesis? My hypothesis is that A and X will have an impact on Y. I have carried out a multiple regression analysis. I have 4 IV’s, A,B,C and D (for ease of explanation) A stands alone and B,C,D are sub-scales to X . The model as a whole appears to be significant p < .001. However, individually the only IV to appear significant is A. B,C,D are not significant p > .o5. Does this mean that I cannot accept my hypothesis, or is it possible to partially accept a hypothesis?? Any help would be amazing, going round in circles here.


Where are the Stack Exchange servers located? And who is the hosting provider for  Stack Exchange?


I have the following code:  public static void main(String[] args)      throws ParserConfigurationException, SAXException, IOException {      DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();     dbFactory.setNamespaceAware(true);     DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();     Document document = dBuilder.parse("NewFile.xml");     String usr = document.getElementsByTagName("username").item(0).getTextContent();     System.out.println(document);  }   This is causing a NullPointerException at String usr line. Any ideas why? The new file is placed in the workspace project folder and i also tried to give the absolute path with no success.  XML file:      <?xml version="1.0"?> <tudorTestUser>     <propertySet>         <property name="username">TudorTest123</property>            <property name="firstName">Ion</property>         <property name="lastName">Vasile</property>         <property name="password">Tester123</property>         <property name="passwordAgain">Tester123</property>     <!-- <property name="location">Bucharest</property> -->         <property name="email">tester@test.com</property>         <property name="Status">active</property>         <property name="thirdParty">No Third Party</property>         <property name="agentID">Tester</property>         <property name="switch">on</property>         <property name="position">Web Master</property>         <property name="clone"></property>         <property name="overrideCode"></property>        </propertySet> </tudorTe


arcpy clean up of variables in cursors vs. loops

I'm new to Python & ArcPy. I'm used to cleaning up temporary variables used in loops after completing the loop to keep my workspace clean. I think I read that variables created in cursors are temporary and deleted once the cursor completes? In the code sample below, what (if any) should my clean up steps be?  counts = {} with arcpy.da.SearchCursor (outFeatureClass.shp, "Zone_ID") as cursor:     for row in cursor:         if not row[0] in counts.keys():             counts[row[0]] = 1         else:             counts[row[0]] += 1 # del row?? cursor??  with arcpy.da.UpdateCursor(outFeatureClass.shp, ["Zone_ID", "N_1"]) as cursor:     for row in cursor:         zone = row[0]         if zone in counts:             row[1] = counts[zone]             cursor.updateRow(row) # del row?? zone?? cursor??  with arcpy.da.UpdateCursor(outFeatureClass4.shp, ["Zone_ID", "N_1"]) as cursor:     for row in cursor:         zone = row[0]         if zone in counts:             row[1] = counts[zone]             cursor.updateRow(row) # del row?? zone?? cursor??


Insert values to fields in iframe on mobile

I've built a script that on mouseover iframe inserts values from the parent site into the form fields inside the iframe and it works great on computers.  If I try to run this on a mobile (iPhone 5) it doesn't insert to values. I've tried to do it on button click(on parent site) on the mobile but still no values in the iframes form fields.  Any ideas of how I can do this?  Best regards, Daniel


so I got Ubuntu Core up and running on a Raspi 3. Now I tried out a few snaps, but when it comes to snaps with a GUI I face a problem (I am connected via ssh). So I run gimp  and it gives me the output: Cannot open display:    That's it. I know that there are often issues with the display output when connected via ssh, but I could not solve it with the export DISPLAY command. Does anyone have a clue? I would like to see gimp open and running on a screen connected via HDMI to the raspi.  I do not want to use SSH forwarding, because for my problem I won't have another device connected to the raspi during runtime.


Executing method in fragment after receiving response from Activity

I have an Activity with two Fragments, and I am getting a list of users from my database and storing in an ArrayList in my MainActivity. The problem is that the Adapter is in one of my Fragments. So what I want to do is call this method "initAdapter" inside my Fragment only when I finish getting the data from my Activity.  I tried this:  ExternsFragment fragment =     (ExternsFragment) getSupportFragmentManager().findFragmentById(R.id.viewPager); fragment.initAdapters(listUsers);   But I am getting an "Attempt to invoke a virtual method on a null object or reference" error. So I think this is not the right way to do that. How can I execute this method inside my Fragment only after I finish another in my Activity?  This is my stack trace:  09-13 18:05:30.948 23890-23890/com.construct.test I/System.out: 200 09-13 18:05:30.953 23890-23890/com.construct.test D/AndroidRuntime: Shutting down VM 09-13 18:05:30.993 1121-24364/? I/EventLogSendingHelper: Sending log events. 09-13 18:05:31.103 23890-23890/com.construct.test E/AndroidRuntime: FATAL EXCEPTION: main                                                                     Process: com.construct.test, PID: 23890                                                                     java.lang.NullPointerException: Attempt to invoke virtual method 'void com.construct.v2.activities.teams.ExternsFragment.initAdapters(java.util.List)' on a null object reference                                                                         at com.construct.v2.activities.teams.ActivityTeams$3.onResponse(ActivityTeams.java:165)                                                                         at retrofit2.ExecutorCallAdapterFactory$ExecutorCallbackCall$1$1.run(ExecutorCallAdapterFactory.java:70)                                                                         at android.os.Handler.handleCallback(Handler.java:751)                                                                         at android.os.Handler.dispatchMessage(Handler.java:95)                                                                         at android.os.Looper.loop(Looper.java:154)                                                                         at android.app.ActivityThread.main(ActivityThread.java:6123)                                                                         at java.lang.reflect.Method.invoke(Native Method)                                                                         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)                                                                         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:757) 09-13 18:05:31.104 3100-4960/? W/ActivityManager:   Force finishing activity com.construct.test/com.construct.v2.activities.teams.ActivityTeams


I always install Proftp on Centos and it works well. I am now installing on Debian 9 and there is an error in the configuration file. Installation is no problem. And the configuration file is what the installation creates, I do not change anything in the file and this error already exists. root@altais:~# systemctl status proftpd ● proftpd.service - LSB: Starts ProFTPD daemon    Loaded: loaded (/etc/init.d/proftpd; generated; vendor preset: enabled)    Active: failed (Result: exit-code) since Fri 2020-07-31 16:45:57 -03; 3s ago      Docs: man:systemd-sysv-generator(8)   Process: 45717 ExecStart=/etc/init.d/proftpd start (code=exited, status=1/FAILURE)  Jul 31 16:45:57 altais systemd[1]: Starting LSB: Starts ProFTPD daemon... Jul 31 16:45:57 altais proftpd[45717]: Starting ftp server: proftpd2020-07-31 16:45:57,902 altais proftpd[45724]: warning: unable to determine IP address of 'altais' Jul 31 16:45:57 altais proftpd[45717]: 2020-07-31 16:45:57,902 altais proftpd[45724]: error: no valid servers configured Jul 31 16:45:57 altais proftpd[45717]: 2020-07-31 16:45:57,902 altais proftpd[45724]: fatal: error processing configuration file '/etc/proftpd/proftpd.conf' Jul 31 16:45:57 altais proftpd[45717]:  failed! Jul 31 16:45:57 altais systemd[1]: proftpd.service: Control process exited, code=exited status=1 Jul 31 16:45:57 altais systemd[1]: Failed to start LSB: Starts ProFTPD daemon. Jul 31 16:45:57 altais systemd[1]: proftpd.service: Unit entered failed state. Jul 31 16:45:57 altais systemd[1]: proftpd.service: Failed with result 'exit-code'. root@altais:~#   Has anyone been there and can you help me?


If I have an array that looks like this:  $members = array( array(     'id'=>2,     'name' => 'Bob',     'status' => 1     ), array(     'id'=>4,     'name' => 'Fred',     'status' => 1     ), array(     'id'=>5,     'name' => 'Sally',     'status' => 0     ), array(     'id'=>1,     'name' => 'Fred',     'status' => 1     ), array(     'id'=>3,     'name' => 'Jane',     'status' => 0     ), );   How can I sort the entries so that they show in alphabetical order by name?


I lost the sa password on a machine, and when I log in to the machine directly using an account in the admin group, SQL Server Management Studio will not allow me to log in using Windows authentication.  My plan was to simply log into the server, connect via Windows Authentication, and reset sa to use a new password. Since I cant' connect via Windows Authentication, this won't work.  How else can I reset the sa password?


Using root account to give sudo priviledges for a wordpress install

I'm quite new to Linux but I need to install Wordpress on a Debian Wheezy machine.  I have been reading tens of websites to prepare for this and they seem to say that Wordpress should NOT be installed as the root user. I created a normal user called Myname and I will try to do the installation with that user. But in all the tutorials the SUDO-command seems to be used.   So my questions are these:   How do I, acting as root user, give the Myname user SUDO priviledges? How can I know which SUDO priviledges I should be giving Myname? Do I need to be specific or can I give a broad range of them?


Itemized in a box with auto scaled width

I would like to have an list (itemize) with a box around it. I know that \framebox doesn't work, because it doesn't support line breaks. Also I don't want to use \parbox because I'd have to set the width myself. I'm doing some work where I have tons of boxes and thus I don't want to always care about the width. It should auto scale, like \framebox does it.  Edit:  What I did is the following: (until now) [you need to include \usepackage{minibox} package]  \newcommand{\ltwo}[2] { \framebox{\minibox{$\bullet$ #1 \\ $\bullet$ #2}}} \newcommand{\lthree}[3] { \framebox{\minibox{$\bullet$ #1 \\ $\bullet$ #2 \\ $\bullet$ #3}}}  \newcommand{\lfour}[4] { \framebox{\minibox{$\bullet$ #1 \\ $\bullet$ #2 \\ $\bullet$ #3 \\ $\bullet$ #4}}}   So I write:  \lthree{Hello}{The width will adjust to the width of this line}{ but not this}   I know I could write recursive macros, but I'm too inexperienced atm.


Regular expression targeting numbered list is not working

The string I'm testing against:  First-line normal. 1. First item 2. Second item 3. Third item 4. Fourth item... 4. Should not remove 5. Fifth item 6. Sixth item 7. Seventh item 8. Eight item 9. Ninth item   Code is:  def remove_lists(string):     return re.sub(r'^\d+\. ','',string,re.MULTILINE)   I'm expecting this to remove all the numbered starts of each line, resulting in:  First-line normal. First item Second item Third item Fourth item... 4. Should not remove Fifth item Sixth item Seventh item Eight item Ninth item   However, it doesn't remove anything! If I remove the carat from the start of the line, it removes all but the last two items (no idea why!) but it also removes the 'should not remove'.  I've tested this on regexr.com, and pythex.org, and it works correctly on both sites. What is going on???


All three of my professors asked me to write the first draft of my Letter of Recommendation.

I just finished writing for one of them but I still have two more to write. Though my interactions with all three of them have been on different occasions, there are still limited things I can write about myself without overdoing things. I am just not sure how should I approach writing the rest two? Should I just repeat everything I wrote in the first one? I am quite sure they will add/remove a couple of lines only. So if I just copy the contents, they will look all the same. If I don't then I fear I will miss important points about myself.


Soo I was modeling when I came across a face that a loop cut didn't work on. I googled it and everyone was saying it would be like an interior face behind the normal face but it was the only face.  Here are some pics


Regex to find the word just before and after a keyword?

What RegEx would match the word (including special characters) right after a keyword?  E.g. In the following text, using the keyword "equals", the RegEx would match "'1'", "Two" and "3"  Status equals '1' or Status equals Two or Status equals 3


Why use $_SERVER['REQUEST_METHOD'] and not $_POST

If I am testing whether my HTML form (with method post) has been submitted (vs a fresh page load), is there any benefit to using  if( $_SERVER["REQUEST_METHOD"] == "POST" ) { }  as opposed to  if( $_POST) { }.   Let's assume that either way, after this check I am checking for isset( $_POST['my_var'] ).


Monotonicity of the sequences $\left(1+\frac1n\right)^n$, $\left(1-\frac1n\right)^n$ and $\left(1+\frac1n\right)^{n+1}$

I am working on the following sequences.   $$x_n=\left(1+\frac1n\right)^n \qquad z_n=\left(1-\frac1n\right)^n \qquad y_n=\left(1+\frac1n\right)^{n+1}$$  I am trying to prove that $x_n$ and $z_n$ are increasing sequences and $y_n$ is a decreasing sequence.   I proved that $x_n$ is increasing using the binomial theorem: as $n$ increases, the number of terms in my sum increases. Also, for $k\ge1$ and $n\ge k$ the $(k+1)th$ term in our sum is $$\frac{n(n-1)(n-2)\cdots(n-k+1)}{k!}\left(\frac{1}{n}\right)^k$$ which can be rewritten as $$\frac{1}{k!}\left[\left(1-\frac1n\right)\left(1-\frac2n\right)\cdots\left(1-\frac{k-1}{n}\right)\right]\qquad(1)$$ Here, the product in $(1)$ increases as $n$ increases. I am in trouble proving that $z_n$ and $y_n$ are decreasing. Could you suggest me an approach to this problem please?   Thank you.  Edit  Since I obtained an answer for $y_n$, I kept working on $z_n$. I took the continuous function $z(x)=(1-\frac1x)^x=\exp \left\{x\log(1-\frac1x)\right\}$. Then I derived it to obtain $$z'(x)=\exp\left\{x\log(1-\frac1x)\right\}\left[\log(1-\frac1x)+\frac{x}{(x-1)/x}\cdot\frac{1}{x^2}\right]$$ But $$z'(x)=\exp\left\{x\log(1-\frac1x)\right\}\left[\log(1-\frac1x)+\frac{1}{x-1}\right]$$  $e^a$ is always positive. Hence the sign of $z'(x)$ depends on what we have between square brackets, which is greater than zero (I don't know how to prove it; I used a plot) for $x\ge1$.  Hence $z_n$ is increasing.


Shrinkwrap a curve without affecting its geometry?

I'm trying to create a "cable" (i want to animate the start/end-point of it later) on a surface.  As you can see the shrinkwrap modifier is doing a pretty good job:   But as soon i try to bevel the curve it looks completely destroyed:   Is there a way to maintain the curve without affecting the geometry?


What is the the most profitable way of transferring euro to usd in the states?

What is the the most profitable way of transferring euro to usd in the states. First answer it by bank transfer. I guess there would be a lot of fees. Another way i guess is through bitcoin since it is universal but i do not know how safe this is and how you can transform money credit to bitcoins and vice versa. Recently i read about stellar network which provices transactions in multi-currency system through gateways that receive credit in a currency and transform it in a stellar.


Show $\mathbb{Q}(\sqrt{2},\sqrt{3})$ is a simple extension field of $\mathbb{Q}$.     Since $\sqrt{2},\sqrt{3}\in \mathbb{Q}(\sqrt{2},\sqrt{3})$, and $\sqrt{2}\sqrt{3}=\sqrt{6}\in \mathbb{Q}(\sqrt{2},\sqrt{3})$, so $\mathbb{Q}(\sqrt{2},\sqrt{3})=\mathbb{Q}(\sqrt{6})$, hence $\mathbb{Q}(\sqrt{2},\sqrt{3})$ is a simple extension field of $\mathbb{Q}$.     Does my argument right? The only information I have is : A field extension $E$ of $F$ is called a simple extension if $E = F(\alpha)$ for some $\alpha \in E$.


Is there a website to find someone to travel with?

I've heard of Travel Buddies and a few other websites like it, but I'm skeptical. Has anyone used a site and actually traveled with someone??


Suppose that the function $f:[a,b]\rightarrow \mathbb{R}$ is continuous. For a natural number $k$, let $x_1,\cdots,x_k$ be points in $[a,b]$. Prove there is a point $z\in[a,b]$ at which $f(z)=\frac{f(x_1)+f(x_2)+\cdots+f(x_k)}{k}$.    This can be proved by showing   $\hspace{130pt}f(a)<\frac{f(x_1)+f(x_2)+\cdots+f(x_k)}{k}<f(b)$  and using the intermediate value theorem to say there exists a point $z\in [a,b]$ such that the statement is true.  I'm not sure how to show this though. Any suggestions?


Referencing List by indexVar in lightning component

I have nested list in my lightning component and now I want  to refer records of list using indexVar.  Has anyone done this before?  <aura:iteration items="{!v.records}" var="row" indexVar="rowCnt">  Like `{!row[rowCnt]}?`  </aura:iteration>


I'm coding a bot using discord.js. I'm trying to setup a system where the bot is allowed to send a message as long as it is not blacklisted. However, every time I run the function, I get this message: ReferenceError: res is not defined I've tried moving var res so many times and I can't figure it out. Does anyone know how to arrange this properly? function getNum() {      var randNum = [         "1",         "2",         "3",     ];     // Blacklist Entries Start     var blacklistNum = [         "1"     ];     // Blacklist Entries End     return randNum[Math.floor(Math.random()*randNum.length)];     return; } if(res === blacklistNum) {     getNum(); }  getNum(); message.channel.send(res);


How to find $ \int_0^\infty \dfrac x{1+e^x}\ dx$

How to find  $$ \int_0^\infty \dfrac x{1+e^x}\ dx=\ ...? $$  I don't know where should I start with. The correct answer from my textbook is $\frac{\pi^2}{12}$. This is my homework with 10 questions but I can only answer 9 questions, this one I'm stuck. Can anyone help me? Thanks.


Problems compiling math w/Beamer when running as non-administrator

I am having problems compiling a Beamer-presentation w/math symbols when running as non-administrator under Win7-64. (I use TeXStudio 2.10.8 with a complete install of MiKTeX 2.9.) To give an example, the following works well as an administrator:  \documentclass{beamer}   \begin{document}   \begin{frame}       Test: $Y_t$   \end{frame}   \end{document}    By contrast, when running as a non-administrator, I need to comment out the math for compilation to work:  \documentclass{beamer}   \begin{document}   \begin{frame}       Test: %$Y_t$   \end{frame}   \end{document}     Compilation under the article-class w/math works well, so the problem seems to be Beamer-related. The messages I get when trying to compile as non-administrator below. Anyone any suggestion for how I can solve my problem?  From messages:     Process started: pdflatex.exe -synctex=1 -interaction=nonstopmode "test".tex      Sorry, but miktex-makemf did not succeed for the following reason: The mathkerncmssi source file could not be found. The log file hopefully contains the information to get MiKTeX going again: C:/Users/sucarrat/AppData/Local/MiKTeX/2.9/miktex/log/miktex-makemf.log You may want to visit the MiKTeX project page, if you need help.      Sorry, but miktex-makepk did not succeed for the following reason: PK font mathkerncmssi8 could not be created. The log file hopefully contains the information to get MiKTeX going again: C:/Users/sucarrat/AppData/Local/MiKTeX/2.9/miktex/log/miktex-makepk.log You may want to visit the MiKTeX project page, if you need help.   Process exited with error(s)  From log:     Font shape OT1/cmss/m/n' in size <4> not available(Font) size <5> substituted   pdflatex.exe (file pdftex.map): cannot open font map file]\tf@nav=\write6\openout6 =test.nav'.   Size substitutions with differences(Font) up to 1.0pt have occurred.      pdflatex.exe (file pdftex.map): cannot open font map file]\tf@nav=\write6\openout6 = `test.nav'.      Size substitutions with differences(Font) up to 1.0pt have occurred.


I have to go to school.  I have to go to the school.  Which is correct sentence?  Can we use article before the word "School"?


Can you download Android applications with Ubuntu?

I just want to know if you can, and what kind of applications can be downloaded.


I found in dictionary that phrase How do you do is equivalent to phrase Nice to meet you. But I never heard it in any movie or tv serial. Is that right or not


Need to retrieved all related object of Opportunity object

I am able to get all objects which are related in opportunity object by looking into opp-->Fields.I can see related object lookup(Object name).but how can i know other objects which are using opportunity lookup/master-details relationship. Please suggest


"All I need (is/are) cigarettes and alcohol": which one is correct?

In one of Oasis's songs — Cigarettes and Alcohol — there are two sentences that make me confused:     All I found was cigarettes and alcohol   ...and...     All I need is cigarettes and alcohol   Why would is and was be correct in these sentences instead of are and were, since they're referring to more than one thing?


Do black holes violate the uncertainty principle?

If black holes have mass but no size, does that imply zero uncertainty in position? If so, what does that imply for uncertainty in momentum?


Can we find a topological space $X$ such that $\mathbb{R}$, with usual topology is homeomorphic to $X\times X$ with product topology?


Is there any plugin that would allow the cover images from eBooks to be seen in  Nautilus file directory windows (in Ubuntu 14.04 / Unity)? I'm looking for something that would give me cover images like I see for PDF eBooks in Nautilus.


how to match "test\w*" but not "tester" with a single regex expression

Say I have the following string:  test tester tested testing   I wish to match every word that begins with test, but not the word tester. The pattern test\w* does most of the job, but I have no idea how to add that tester should not be matched. A working pattern should give 3 matches on the string.


Perhaps this is a dumb question.   I write a small pdf-book on coding and use there many examples using listings package.  But the amount of code expands text too much, for every 5 lines of text there is 10-20 lines of listings.   I wish there was a way to show code on demand (like spoiler).   May be there is some format supported by latex which would allow to do such thing ?


I want to have a List of Figures in my Beamer presentation.  I spent some time searching the web for a solution and only found desperate people telling others that it's not possible, i.e.  or .  I also made some experiments on my own, i.e. "abuse" tocloft to do the job. However, even \usepackage{tocloft} causes pdflatex to fail with ! LaTeX Error: \l@section undefined. (and lying to tocloft by defining the command as empty beforehand doesn't to any good either).  I can't really see why it should be that difficult to make a List of Figures in beamer, since \tableofcontents works flawlessly.   I'm not afraid of doing some coding on my own, but I'm not deep enough into TeX to really understand the magic behind the "List of Figures", "Table of Contents" and alike.  Is anyone out there having suggestions or links that might help me figure this out?  \documentclass{beamer}  % uncomment the following line % to get the error message % `! LaTeX Error: \l@section undefined.`  %\usepackage{tocloft}   % uncomment the following lines INSTEAD % to lie to tocloft % and get the next error message  %\makeatletter %\newcommand\l@section{} %\makeatother %\usepackage{tocloft}  \begin{document}  \begin{frame}{A frame} \begin{figure} \mbox{A} \caption{An 'A'} \end{figure} \end{frame}  \begin{frame}{List of Figures} \listoffigures \end{frame}  \end{document}   EDIT: Solution  Starting from Marco Daniels answer to my question, I modified his code to reflect my needs. Here is what I came up with. Please feel free to comment, improve and reuse this.  \RequirePackage{ifthen}  \makeatletter  \AtEndDocument{%   \clearpage   \beamer@tempcount=\c@page\advance\beamer@tempcount by -1%   \if@filesw   \newwrite\tf@lof   \immediate\openout\tf@lof\jobname.lof\relax   \newwrite\tf@lot   \immediate\openout\tf@lot\jobname.lot\relax   \fi }  \long\def\beamer@makecaption#1#2#3#4{%   \def\insertcaptionname{\csname#1name\endcsname}%   \def\insertcaptionnumber{\csname the#1\endcsname}%   \edef\insertframenumber{\theframenumber}%   \ifthenelse{\equal{#3}{\empty}}{%       \def\insertlistcaption{#2}%   }{%     \def\insertlistcaption{#3}%   }   \def\insertsource{#4}%   \def\insertcaption{#2}%   \ifthenelse{\equal{#1}{figure}}{%       \addtocontents{lof}{\protect\listoffigureformat{\insertcaptionnumber}{\insertlistcaption}{\insertframenumber}{\insertsource}}{}{}%   }{}   \ifthenelse{\equal{#1}{table}}{%       \addtocontents{lot}{\protect\listoftableformat{\insertcaptionnumber}{\insertlistcaption}{\insertframenumber}}{}{}%   }{}   \nobreak\vskip\abovecaptionskip\nobreak   \sbox\@tempboxa{\usebeamertemplate**{caption}}%   \ifdim \wd\@tempboxa >\hsize   \usebeamertemplate**{caption}\par   \else   \global \@minipagefalse   \hb@xt@\hsize{\hfil\box\@tempboxa\hfil}%   \fi   \nobreak\vskip\belowcaptionskip\nobreak% }  \def\listoffigureformat#1#2#3#4{%   \makebox[2ex][r]{#1}%   \hspace{1ex}%   {\usebeamercolor[fg]{bibliography entry author} #2}%   \ifthenelse{\equal{#4}{\empty}}{}{ -- #4}%   \dotfill%   \makebox[2ex][r]{#3}\par% } \def\listoffigures{%   \setlength{\leftskip}{3ex}   \setlength{\parindent}{-3ex}   \@starttoc{lof}% } \def\listoftableformat#1#2#3{\makebox[2ex][r]{#1}\hspace{1ex}#2\dotfill\makebox[2ex][r]{#3}\par} \def\listoftables{%   \setlength{\leftskip}{3ex}   \setlength{\parindent}{-3ex}   \@starttoc{lot}% }  \long\def\@caption#1[#2]#3{   \par\nobreak   \begingroup     \@parboxrestore     \if@minipage       \@setminipage     \fi     \beamer@makecaption{#1}{\ignorespaces #3}{\ignorespaces #3}{\ignorespaces #2}\par\nobreak     \endgroup}  \makeatother


I'm trying to create a individual List with a templated value, but unfortunately I can not link from my List to the ListElements with templates.  In my main I call List<int> list1; to create a instance of the class List. A List contains multiple ListElements that contain the value, that should be templated.  Compiler throws an error at   ListElement* first; ListElement* last;   in List.h. It says C2955 - 'ListElement' : use of class type requires type argument list  List.h  #pragma once #include <string> #include "ListElement.h" template<class T> class List { private:     ListElement* first;     ListElement* last; public:     List();     ~List();     void printList();     void pushBack(T value);     void pushFront(T value); };   List.cpp  #include <iostream> #include "List.h"  template<class T> List<T>::List() {     first = NULL;     last = NULL; }  template<class T> List<T>::~List() { }  template<class T> void List<T>::pushBack(T value) {     if (last)     {         ListElement* tmp = last;         last = new ListElement(value);         last->setPrev(tmp);         tmp->setNext(last);     }     else     {         first = new ListElement(value);         last = first;     } }  template<class T> void List<T>::pushFront(T value) {     if (first)     {         ListElement* tmp = first;         first = new ListElement(value);         first->setNext(tmp);         tmp->setPrev(first);     }     else     {         last = new ListElement(value);         first = last;     } }  template<class T> void List<T>::printList() {     if (first)     {         ListElement* tmp = first;         while (tmp)         {             std::cout << tmp->getValue() << std::endl;             if (tmp != last)                 tmp = tmp->getNext();             else                 break;         }      }     else      {         std::cout << "List is empty!" << std::endl;     } }  template class List<int>; template class List<std::string>;   ListElement.h  #pragma once #include <string> template<class T> class ListElement { private:     ListElement* next;     ListElement* prev;     T value; public:     ListElement(T val);     ~ListElement();     ListElement* getNext() { return next; }     ListElement* getPrev() { return prev; }     void setNext(ListElement* elem) { next = elem; }     void setPrev(ListElement* elem) { prev = elem; }     T getValue() { return value; } };   ListElement.cpp  #include "ListElement.h"  template<class T> ListElement<T>::ListElement(T val) {     value = val; }  template<class T> ListElement<T>::~ListElement() { }  template class ListElement<int>; template class ListElement<std::string>;


I wan't to install wine in Ubuntu but  after type this sentence a message appear that says :   E: Could not open lock file /var/lib/dpkg/lock - open (13: Permission denied) E: Unable to lock the administration directory (/var/lib/dpkg/), are you root?   what is the solution of this problem?


Question about the main clause of conditionals

I know the four types of conditionals. In the if clause, I know that “if” could be replaced by “when” and “should”. On the other hand, I do not know if this would be possible with the main clause. Can we replace the word “would” with other words, like “should or “could”?


Isn't the uncertainty principle just non-fundamental limitations in our current technology that could be removed in a more advanced civilization?

From what I understand, the  states that there is a fundamental natural limit to how accurately we can measure velocity and momentum at the same time. It's not a limit on equipment but just a natural phenomenon.  However, isn't this just an observational limit? There is a definite velocity and momentum, we just don't know it. As in, we can only know so much about the universe, but the universe still has definite characteristics.  Considering this, how do a wide range of quantum mechanical phenomena work? For example, quantum tunneling - its based on the fact that the position of the object is indefinite. But the position is definite, we just don't know it definitely. Or the famous light slot experiment? The creation of more light slots due to uncertainty of the photon's positions?  What I am basically asking is why is a limit on the observer, affecting the phenomenon he is observing? Isn't that equivalent to saying  because we haven't seen Star X, it doesn't exist? It's limiting the definition of the universe to the limits of our observation!


I've tried Nero SecurDisc for writing Copy Protected, Password Protected files on DVD which requires Nero SecurDisc Viewer to decrypt them. But It doesn't seem to have an option to protect/encrypt filenames.  Is there any similar utility that has both options, for example like WinRAR has an option to encrypt names + data?  I was thinking about compress the files into .rar with encryption and then write them on DVD. Would it do the same that i'm trying to do?


What is the $n$ times iterate of $f(x)=\frac{x}{\sqrt{1+x^2}}$?

We were asked to determine  the composition $f \circ f \circ f \circ \cdots \circ f $,  $n$ times, where $f(x)=\dfrac{x}{\sqrt{1+x^2}}$.  Has anyone an idea?


What are the '.' and '..' outputs in `ls -lah`?

Just wondering. I'm new so sorry if this is stupid. Output: total 24K drwxrwxr-x 6 lveri tas lveritas 4.0K Oct 24 00:04  . drwxrwxr-x 7 lveritas lveritas 4.0K Oct 20 22:22  .. drwxrwxr-x 3 lveritas lveritas 4.0K Oct 20 22:22 'Common Files' drwxrwxr-x 2 lveritas lveritas 4.0K Oct 20 22:22 'Internet Explorer' drwxrwxr-x 2 lveritas lveritas 4.0K Oct 20 22:22 'Windows Media Player' drwxrwxr-x 3 lveritas lveritas 4.0K Oct 20 22:22 'Windows NT'


If Z has a normal distribution with mean 0 and variance $\sigma^{2}$, and $Y=Z^{2}$, what would the density function of Y be?

How would I go about finding this density function? Thanks


Let ${a_n}$ be a sequence such that there exists an M > 0 such that for all n ∈ N one has $|a_{n+1} − a_n|$ ≤ M/$2^n$  Prove that ${a_n}$ is a Cauchy sequence.  My attempt: I tried to use the triangle inequality to prove that for all m$>$n, $|a_m - a_n|$<$\epsilon$ but I am unable to get anything useful out of the inequalities I'm getting.


How to create thread safe GetEventHandler()?

public partial class JobDataDuplicatorForm : Form {     public JobDataDuplicatorForm(IJobDataDuplicatorEngine engine)     {         _engine.CopyStartedEvent += GetEventHandler(OnCopyStarted);         _engine.CopyEndedEvent += GetEventHandler(OnCopyEnded);         ...     }      private static EventHandler GetEventHandler(Action action)     {         return (sender, args) => action();     }      private void OnCopyStarted()     {         copyStatus.Text = "Copy progress: ";         generateButton.Enabled = false; // Cross-thread operation not valid     } }   I have the following exception:  Additional information: Cross-thread operation not valid: Control  'generateButton' accessed from a thread other than the thread it was created on.   Can I fix the exception by changing GetEventHandler() instead of wrapping each button in different places like this   Invoke((MethodInvoker)delegate {         generateButton.Enabled = false;         }); ?  How can I do this?


I am using android browser (Android 4.1) on Tab which have  1024 x 600 pixels resolution and today I found that layout is not proper, Its messing below is what I am seeing,


Use of optional argument stretch in \parbox

I'm having some difficulty on how to use the "stretch" optional argument of \parbox. Is it supposed to equally interspace lines of text inside a box of determined size?  If I code it like:   \documentclass{article} \begin{document}   Text   \fbox{\parbox[c][15cm][s]{5cm}{I want to stretch this text inside this box}} \end{document}   This is the outcome I get:   I also experimented with \parbox and got some unexpected outcomes. In the following code, I merely deleted the alignment optional argument (default is center) from the previous test:  \documentclass{article} \begin{document} Text \fbox{\parbox[15cm][s]{5cm}{I want to stretch this text inside this box}} \end{document}   As a result, this came out:   Which confused me, because I thought deleting the first optional argument would simply put it in default. I also didn't get why the text from the mandatory argument was substituted by the letter "s", a shortcut for "stretch" in the third optional argument.  Another test:   \documentclass{article} \begin{document} Text \fbox{\parbox[15cm]{5cm}{I want to stretch this text inside this box}} \end{document}   Which yielded me:   In this last one, I deleted the stretch optional argument, but the height of the box was not drawn.  Why did I get those results? I'm barely a starter at TeX, so might me missing obvious points on the use of optional arguments.


i have a general question.  if there is a general LP problem  $c^Tx$ s.t $A\cdot x \le b$, and $x \ge 0$ and assuming that the components of $c$ are non-zero entries then how can I prove that when $x$ satisfies $a\cdot x < b$ (notice the strict inequality here) and $x > 0$, then $x$ cannot be an optimal solution?


Prerequisite for research in discrete mathematics

I hope to apply graduate math department for MS/PhD in math. My area of interest are discrete math, combinatorics, graph theory... etc.Now I have few questions :  Which are the prerequisites for these courses ? and Which grade of my undergraduate are more important ? I am also a bit confused that whether I will apply for a pure or applied dept ?


What is the best way to restrict access to adult content?

I bought my kids a PC and installed 12.04 (Unity) on it.  The bottom line is, I want my children to use the computer unsupervised while I have confidence they cannot access anything inappropriate.  What I have looked at:  I was looking at Scrubit a tool which allows me configure my wifi router to block content and this solution would also protect my other PC and mobile devices.  This may be overkill as I just want the solution to work on one PC.    I also did some Google searches and came across the application called .  My experience of OSS is that the best solutions frequently never appear first on a Google search list and in this case I need to trust the methods therefore my question is very specific.   I want to leverage your knowledge and experience to understand What is the best way to restrict adult content on 12.04 LTS as this is important to me.  It maybe a combination of things so please don't answer this question "try this or that", then give me some PPA unless you can share your experience of how good it is and of course if there are any constraints.


I've just build a naturalist in my game, and I want to use it's ability to build a national park, but wherever I place it the button doesn't seem to light up.  What determines if a tile is valid as a national park?


select special rows from feature using condition in ArcGIS ModelBuilder?

I am using ModelBuilder and would like to delete specific rows of a feature where the value of two columns are equal.  For instance: if there are columns a,b,c,d and rows 1,2,3,4. I would like to delete the rows where a=c. For that, it is first needed to select those features. When I enter the syntax in the query builder a = c I receive error (000229) and it does't work. I have tried another selection method (Make feature Layer, Selection by Attribute) I am using ArcGIS Desktop 10.2.


single word for the condition of trust issue due to repeated disappointment in the past

I have seen the word before but I forgot what it is. The word is to describe a mental/emotion of a person when the past experience has given him repeated disappointment on a certain thing. The person is getting used to the feeling and adapt to not expecting the high quality outcome.


Are there any matrices satisfying $|A+B|=|A|+|B|$

Are there any $n \times n$ $(n \ne 1)$ matrices satisfying $$Det(A+B)=Det(A)+Det(B)$$  Trivially the above equation is True for either $A=O$ or $B=O$ or $ A=B=O$  For $2 \times 2$ matrix i have tried  as follows:  Let $$A=\begin{bmatrix} a &b \\  c & d \end{bmatrix}$$  and $$B=\begin{bmatrix} p &q \\  r &s \end{bmatrix}$$  Then we have  $$Det(A+B)=(a+p)(d+s)-(b+q)(c+r)$$  $$Det(A)+Det(B)=ad-bc+ps-rq$$  Equating both we get  $$as+pd=br+qc$$  which is satisfied by infinite values of $a,b,c,d,p,q,r,s$   One such pair is  $$A=\begin{bmatrix} 2 &10 \\  2 & 3 \end{bmatrix} $$ and  $$B=\begin{bmatrix} 4 &1 \\  2 &5 \end{bmatrix}$$  is there any general way to find the matrices of higher order?


can "not" substitute a negative independent clause

If I said, "I will dance in the production (pause and sigh) not because my mom wants me to..." is "not" negating "because my mom wants me to" or is it serving as a substitute for the negative of "I will dance in the production"?


I bought this Lemond frame online. I have an opportunity to get some components for it before I actually receive the frame. Hoping to get more info on the bike (model/year) in the hope of getting some kind of spec sheet. Any help is appreciated.


How to automatically clear items in Trash after a week?

I'm using macOS High Sierra. It has a feature to automatically clear items in Trash after they are deleted for 30 days. But I want to clear items in a week. Is it possible?


Dedicated-purpose, single application linux boxes

I'm designing an app that will be deployed/installed to a linux machine (perhaps Archlinux, but could be any distro and in fact I would actually prefer something lightweight and inside the Debian family if at all possible). This machine will not be a "general purpose" or multiple application machine: it's sole purpose is to run my app at startup and close my app at shutdown. No other end-user apps would be installed on this machine.  I'm looking for a way to:   When the user powers on the machine, instead of the normal Ubuntu/OS startup --> BIOS --> splash screen --> login process, they just see a splash screen for my app (while the system and app boots up) and then my app loads with its own look and feel While using the machine, they cannot access any other apps, shells or other part of the operating system; all they have access to is my app When running, the app takes up the entire screen and its window cannot be minimized or resized The app (as software) cannot be turned off or killed while running, except... Turning off the machine (physically powering it down) shuts down the app gracefully and shuts down the underlying OS as well   Hence, the end user never knows that the machine is running on top of linux; to them, the app is the only thing "living" on the machine.  This has to be possible seeing that Android is just a wrapper around Linux, and there are thousands of other devices that just run a single app and nothing more.  This will likely be a C binary that launches a Java desktop application as the actual app.  Any ideas as to how I can accomplish the items mentioned above?


Difference Between Sequential Workflow & State machine workflow?

What is the difference between Sequential Workflow and Stater machine workflow? What context should I take account to when choosing one of them?


If I multiclass into 2 or more spellcasting classes, how do I determine my known/prepared spells?

If I multiclass into 2 or more classes/subclasses that can cast spells, how do I determine what spells I know or can prepare?  For instance, if I am playing a multiclassed character with 1 level in warlock, 2 levels in bard, and 3 levels in paladin, how do I determine which spells I know/have prepared?    Related:


How to get rid of .0 on end of whole float number

I am trying to get rid of the .0 left behind a float number when I add whole numbers together. ex. if i do 10+10 it will print out 20.0 but i want it to print out 20 unless there is a decimal in the number. P.S ive been looking all over on this site and cant find the anser to my question so why did someone make this a duplicate makes no sense.  float numOne = Float.parseFloat(numberOne.getText());     float numTwo = Float.parseFloat(numberTwo.getText());     float anser = numOne+numTwo;     String AR = String.valueOf(anser);         anserLabel.setText(AR);


Both $\log_34$ and $2^\frac 1 4$ are somewhere in between $1$ and $2$. I know I can get approximate values but they are difficult to calculate by hand so I conclude it's not the way I'm supposed to do the exercise.  So how can I compare the two numbers without using a calculator?


I can ask any of:     Do you know a breakfast place nearby?   Do you know a nearby breakfast place?   Do you know a good breakfast place?   but I really can't ask:     Do you know a breakfast place good?   Is there a general rule for determining whether an adjective must come before the noun or may come, Spanish-style, after it?


What is the difference between assigning a new DataTable, DataTable.Clear(), DataTable.Reset() and DataTable.Rows.Clear()?

I am using datatables to bind a DataSource to a GridView. This is how I do it.  I declared the dattable as follows.   private DataTable dt_CompanyNames;   Then  private void get_CompanyNames() {      dt_CompanyNames = new DataTable();      dt_CompanyNames = objDesignation_Bll.Get_CompanyNames();      gridCompanies.DataSource = dt_CompanyNames;      gridCompanies.DataBind(); }   So my question is What If I do those in below ways.  First I have to do this.  private DataTable dt_CompanyNames=new DataTable();   Then in my method I am using these statements.  1) Method 1   dt_CompanyNames.Clear();   2) Method 2   dt_CompanyNames.Rows.Clear();    3) Method 3   dt_CompanyNames.Reset();   4) Or should I stick with my exisiting method?  dt_CompanyNames = new DataTable();   In this method it always create new Datatable when each time this function calls. Is it good?  So what is the difference among those?  Is there one better than the other in terms of efficiency?


What do you call a person who has a relationship with a much younger adult?

What do I call someone who marries or has a sexual relationship with someone much younger than themselves? Their partner is someone who is at least 18 years old.    The term paedophile is not the correct word, because it refers to minors.


I know Googling I can find an appropriate answer, but I prefer listening to your personal (and maybe technical) opinions. What is the main reason of the difference between Java and C# in throwing exceptions? In Java the signature of a method that throws an exception has to use the "throws" keyword, while in C# you don't know in compilation time if an exception could be thrown.


Write with 8bit pointer, read with 32bit pointer

What really happens if we write 4 times 1B of char with 8bit pointer, and then we read that 4B with 32bit pointer? Why this is not recommended, what can happen?


Compute Engine restrict SSH user to specific directory

How to create a new user that could connect Compute Engine instance via SSH but only access /var/www/[username]/html  My instance is running Ubuntu 16.04  Currently, I have only the root user.  Ultimate goal is to create an user that could then connect the instance using Filezilla but would have access only to the specified directory.


Was readin song lyrics of a commercial song written in english and have two questions:   One line goes "can't you see I'm hurting" - is that correct english to use?  One line said "all for you" as implied - (I would do/I eould give) all for you - is it correct english to say all for you in that context?   P.S English is my second language and the songwriter as well I think


Proper usage of biblatex-ieee BibLaTeX style in an IEEEtran document

The package biblatex-ieee provides a style for BibLaTeX which follows the guidelines of the IEEE (citations are numeric and unsorted). Unlike the IEEEtran.bst file, it provides only the bibliographic style, and not the text formatting of the bibliography section.  What happens is that  with  BibLaTeX the font size of the  References section is the same of the other regular sections. It should be smaller, instead.  In other words, if I use the BibTeX approach  \bibliographystyle{IEEEtran} \bibliography{IEEEabrv,references}   I get both the proper bibliographic style and text formatting (smaller font size).    With the BibLaTeX approach instead, the font size is bigger:    Therefore, I have to format the bibliography text by myself, with something like  \usepackage[style=ieee]{biblatex} \addbibresource{references} [...]  \renewcommand*{\bibfont}{\footnotesize} \printbibliography   Which is the right fontsize (that is, the second argument for \renewcommand*) to be used with the IEEEtran class? (and, by the way, why cannot a  BibLaTeX syle specify the text formatting, too?)  As a reference:    asking for clarifications  stating which font sizes shall be used


What does it mean for objects to follow the curvature of space?

In science documentaries that touch on general relativity, it is often said that gravitational pull isn't an actual a pull (as described by classical physics), but rather one body travelling in a straight line on the curved space around another massive body.  I don't know if I misunderstood that or if it's just an oversimplification meant to help the uninitiated understand the concept better, but something doesn't seem to follow. If the Earth travelling around the Sun is just moving along a straight line in the curved space, shouldn't light also be trapped in orbit around the Sun?  I expect the actual equations in the theory also take into account a body's velocity, not just the curvature.


Need help with untar command - want to untar from multiple .tar files and then move files to common directory

I have several tar files (~270) which untar into the following separate directory structure:  00001.tar -> /00001/001/file1.ima  00002.tar -> /00002/001/file2.ima  . . .  00270.tar -> /00270/001/file270.ima  I wondered if there is a specifier in the untar command that would allow me to not only untar the files, but also move the files (file1.ima, file2.ima, . . . file217.ima) to a common directory.  Does anyone know how to do this? Sorry if this is a simple thing to do; I am pretty inexperienced in this (obviously).  Thanks hugely in advance for any help on this!


Why didn't the Jedi Niman specialists train more?

I heard that most of the Niman specialists on the first Battle of Geonosis died in the arena. Why is it that they couldn't  train more? Apparently it's idea is to have everything in moderation. If one trained enough, then the form could probably turn from good at everything to awesome at everything. You might not have as much precision as Makashi, or speed as Ataru, etc., but you'd have no apparent or major weaknesses and a very well rounded strength.


in an given inequality prove that all sides are equal

If $x,y,z$ are the sides of a triangle and $$\left(1+\frac{y-z}{x}\right)^{x}\left(1+\frac{z-x}{y}\right)^{y}\left(1+\frac{x-y}{z}\right)^{z}\geq 1,$$  then prove that $x=y=z$  what i try  assume $\displaystyle f(x)=x\ln\bigg(\frac{k}{x}\bigg)$ and $k>0$  and $\displaystyle f'(x)=-(1+\ln x)$ and $\displaystyle f''(x)=-\frac{1}{x}<0$ for $x>0$  how do i solve it please see it


I'm trying to add a regex pattern to a HTML5 input which has the type of email. I want to invalidate the input if the proceeding character after the @ symbol doesn't contain at least a single character or number, followed by a dot followed by another character or number, e.g: example@example.com // valid because of "e.c" example@example.    // invalid because "e."  I want to retain the default browser validation for email and thus so far have this pattern that seems to match the first valid example I pasted? But looks untidy? \@([a-zA-Z0-9\/.&\s-].[a-zA-Z0-9\/.&\s-])


"to find" or "finding" after the verb "help"

I want to say this sentence:     Could you help me to find a financial support please?   Would it be more correct to say to find or to say finding? Is there a general rule to determine whether to verb or verb+ing is more correct? Is there a better way to construct that sentence?


To use already existing image, I choose 'Media File Selector' Widget. But, it gives me blank page like this when I click on 'Library' to choose already existing image in Drupal-7.    Version of the Media: 1) Media: YouTube (media_youtube) 7.x-2.0-rc4  2) Media (media) 7.x-1.4  In Media browser settings, Allowed file extensions are  (jpg jpeg gif png txt doc docx xls xlsx pdf ppt pptx pps ppsx odt ods odp mp3 mov m4v mp4 mpeg avi ogg oga ogv wmv ico)  Thanks!


I was asked to find the four colour stripes of a 1M ohm (tolerance of 5%)  My question now is don't we have 2 options? I came up with:   Black(0) Brown(1) Blue(x1M) Gold (5%)  Brown(1) Black(0) Green(x100K) Gold(5%)   Is there one right and one wrong or are both of these correct?


How were the moving portraits in the wizarding world created? Why couldn't the trio make a new portrait of Dumbledore during the Horcrux hunt?

I came across similar questions, but my doubt still remains. Yes, there is a portrait of Dumbledore at Hogwarts, and it was impossible for Harry, Ron and Hermione to access it during DH. But why couldn't they create one themselves for guidance during the Horcrux hunt? I know portraits are just imprints of the person and only reflect the personality of the dead person. But there is no denying that the portrait Dumbledore guided Snape through the year. And that the portrait would have been invaluable to Harry, Ron and Hermione.   Is there any information on how these portraits are created and who creates them? If you need an artist to paint Dumbledore, and then enchant the painting, could they have found a muggle artist who could do it for them and then cast the spell themselves? (While they remained disguised. Dumbledore could have been any old man dressed in funny robes. Any story would have worked or they could have performed a memory modification if it came to that)  Given the amount of struggle the trio goes through to figure out Dumbledore's intentions, they must have thought of this. Especially when they ask Phineas Nigellus if he could bring the portrait Dumbledore along.


I know strength is a noun. So in some sentences article is used and in some sentences, an article is not used before Strength. Example I was impressed by his strength. She's doing exercises to build up the strength in her legs.    I would appreciate if anybody can she some light on it?  Parry


I have the following Bash script  case $- in (*H*) echo enabled ;; (*) echo disabled ;; esac set -H case $- in (*H*) echo enabled ;; (*) echo disabled ;; esac pwd last_command="!!" echo $last_command   which prints  disabled enabled /home/user !!   The first line of code checks to see if history expansion is enabled. The second enables history expansion. The third is the same as the first. Then its runs pwd and finally assigns what should be last command to last_command and prints this variable.  The history is not expanding. What is going on?


"I have sent it to X too" vs. "I have sent it to X also"

I have sent this e-mail to Aman also. I have sent this e-mail to Aman too.   Which one is correct? What is the exact difference between the two? Please explain.


How to disable response to IP on a website?

I have an Apache reverse proxy responding to multiple domain names. I only have one public IP address, and all the domains A records points to this address. When I type in the URL research bar of a browser my IP, it is automatically redirected to one of the domain the reverse proxy is responding to. How can I disable this? I don't want the reverse proxy to respond to "direct IP access", but only to "domain name access" (I don't know if it's clear).


PHP web hosting: how to prevent clients to DOS/DDOS?

I'm providing a partial web hosting solution where my clients may upload and execute their own php scripts.  Besides the security routine I'll have to check (off topic here) I would like to know whether it is possible for me to prevent my clients to setup an "attack basement" in there?  I believe that I can't do much except making them sign some policy acceptance...  Also, since there's only a few IP shared by all the hosts, would there be a risk of everyone getting banned?


I have a Nikon d5200 with 18-140 lens and I don't want to invest more on lenses, so I was planning to sell D5200 and buy P900. Please suggest. Will I get decent photos from P900?  I am not a professional photographer.


Knights take over an alien spaceship, go conquering

This is a story I would have read in the '90s, I think. The beginning involves a bunch of aliens landing on Earth back in the Knights on Horseback era. They wave their ray guns around, intending to cow the lowly natives, but the lowly natives are a bunch of knights on horseback, who promptly ride up the ramp, skewer the aliens, and take over the ship. I don't remember much of the plot after than, except they go on as you would expect and conquer right and left.


Shell How install local bulk of packages

I have 20 or 30 deb files within a folder in a local directory, lets say /home/Downloads. Given that the amount of files may vary, I need a script(or command or whatever) which installs all these .deb when executed.  I have no knowledge of scripting on Linux, so the most explicit the answers the better. Thanks in advance


"An High Priest of Good Things to Come" -- why "An"?

I am watching a video of one of the Apostles of the Mormon Church, Elder Holland, which is entitled:     "An High Priest of Good Things to Come"   The video contains this line:     "Speaking of Jesus’ “more excellent ministry” and why He is “the mediator of a better covenant” filled with “better promises,” this author—presumably the Apostle Paul—tells us that through His mediation and Atonement, Christ became “an high priest of good things to come.”"   Can anyone tell me why he is using the phrase "an high priest" instead of the more conventional "a high priest"? Although the text is a translation from the original language, the address was a mass address intended for members of the general laity, rather than purely biblical scholars. Thus it seems that the a is likely to have been deliberately left in, in order to evoke some sense of the word an to an English speaking audience which is not present in the word a, and therefore retain more of the intentionality of the original text...  Could anyone offer an explanation as to what an is doing in this text, in an English Language sense, which a would not have been appropriate for, or would in some way have been detrimental to the message of (or could be considered to be detrimental to the message of)?  Statement of Non-Duplicate Status  I'm after a specific answer for this passage, not just general rules for an and a. I would also like something a little more than "it sounds nicer", which isn't really an answer; preferably something which broaches any subtle differences in meaning between the two words, and the manner in which the sense of passage would be different if it were to utilise a instead of an.  (Link to video for reference: )


Nullexception error when trying to populate array list

I am extremely new with java. I have been working on a project and am completely stumped.  What I am trying to do is I need to build a application that generates an ArrayList of certain students and grades, and then i will be able to manipulate them from there.   I thought I had it down to where I could get it to create the object at the very least, but it looks like that is not the case. It compiles correctly, but when I try to create the object using the Student() constructor with no arguments it gives me the following stack trace:  java.lang.NullPointerException     at Student.addInitialStudents(Student.java:61)     at Student.<init>(Student.java:23)     at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)     at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)     at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)     at java.lang.reflect.Constructor.newInstance(Constructor.java:423)     at bluej.runtime.ExecServer$3.run(ExecServer.java:759)   from reading the stack trace it looks like the issue is in my constructor.  import java.util.ArrayList;  public class Student {      public ArrayList<Student> students = new ArrayList<Student>();     private String studentID;     private String firstName;     private String lastName;     private String email;     private int age;     private int grade1;     private int grade2;     private int grade3;     private int[][] grades;     private int i;     private int x;      /**      * Constructor for objects of class Student      */     public Student(){         addInitialStudents();     }      public Student(String studentID, String firstName, String lastName, String email, int age, int[][] grades)     {         this.studentID = studentID;         this.firstName = firstName;         this.lastName = lastName;         this.email = email;         this.age = age;         this.grades = grades;     }      private void addInitialStudents(){         String[] id = {"1","2","3","4","5"};         String[] fName = {"John", "Suzan", "Jack", "Erin", "Sam"};         String[] lName = {"Smith", "Erickson", "Napoli", "Black", "smith"};         String[] mail = {"John1989@gmail.com","Erickson_1990@gmailcom","The_lawyer99yahoo.com","Erin.black@comcast.net","ssmith@gmail.com"};         int[] listAge = {20, 19, 19 ,22, 28};         int[][] iniGrades =         {             {88, 79, 59},             {91, 72, 85},             {85, 84, 87},             {91, 98, 82},             {99, 87, 92}         };          for (i = 0; i <= 4; i++){              studentID = id[i];             firstName = fName[i];             lastName = lName[i];             email = mail[i];             age = listAge[i];              for (x = 0; x <= 2; x++){                 grades[i][x] = iniGrades[i][x];             }               students.add(new Student(studentID, firstName, lastName, email, age, grades));          }      }      public void getID(){         System.out.print(students.get(0));     }  }   Anyone have any tips on this?   BlueJ is highlighting the line   grades[i][x] = iniGrades[i][x];   I'm sorry if this is a duplicate, but I couldn't find a solution no matter how much research i tried to do and no matter how many changes I make.


How to include bash scripts with relative path?

I have 3 scripts:  Script A:  echo "Hey you!"   Script B:  source ./A.sh   Script C:  source ./libs/B.sh   So scripts A and B in folder "libs" and script C use script B from this directory.  Script C throw Error:     ./libs/B.sh: line 1: ./A.sh: No such file or directory   How to correct use script "including" in this case?  I understand why this error occurs, but I do not understand how to fix it. Also! I do not want to include with full path as / home /.../libs/A.sh etc. I want to create move-free scripts without permanent editing.


After successfully updating my bios,  and I ended up with a blinking cursor on the top left corner of a black screen. No errors, no nothing. The bios now only listed a SATA: <disc name> boot option in place of the usual UEFI ubuntu one. I'm using a GPT partitioning scheme.  I eventually found that the working solution was to properly reinstall grub-efi-amd64. So, how do I do this ?  PS: Actually, i succeeded to reinstall GRUB2 EFI on my own and will post my answer here as I was unable to find any complete how-to on this.


How do I find how much disk space a program is occupying?

How do I find out how much disk space a program such as Skype occupies?  My SSD is getting full, and I want to see what can be deleted.


I have accidentally updated over 3,000 records in one of my tables hosted on Azure. This was not a transaction and I did not have any back ups for this table.  I've read around and found  but when I connect I try to connect I see "SQL server Azure is not supported"  I understand that this tool examines logs to reproduce the data, is there a manual technique to do is, or an alternative compatible tool?  Really grateful for you support.  Thanks.


How to install a soundcard (snd-hda-intel) while being offline

I  have a computer with no access to internet, however, lubuntu 18.04 (also tried with lubuntu 20.04) does not produce sound. It keeps saying "no dummy output". While on a computer with internet access I downloaded "Cube-Get" and downloaded the DKMS package , which included all of the dependencies. I moved the dependencies for the dkms package on to a USB and transferred it to my computer with no internet. While installing , it halted because of broken dependencies. The reason im installing dkms package is because I need the snd-hda-intel driver. Does anyone have any ideas on how I can navigate this problem?


I'm trying to replace my AC adapter with a battery. The AC adapter output is 12v @ 500mA DC. I can get a 12v battery, but I can't find one that outputs exactly 500mA. I'm trying to power a strip of LED lights. So I guess the real question is, do I need to reduce the amperage if the battery is the correct forward voltage for the strip? And if so is there a formula to use to reduce the amps? Lets say I get a 12v battery that outputs 7900mA; what type of resistor do i need to get 7900mA down to 500mA without reducing the voltage?  Thanks.


Is it possible to make a scooter that is propelled by perpetual magnets (without converting it to electricity)?

I am, along with two of my classmates, are planning to make a prototype of a scooter (as in slower, smaller version of a motorcycle) that is propelled by an infinitely turning magnet wheel. Not as a motor or something that converts the motion to electricity, but as an independently perpetual motion-machine that may lead to the movement of the wheels of the scooter. But we have no blueprint or any plan on how to make that happen. Other than this, we are completely clueless on how to make brakes for this type of thing, how to control the speed, and how will generally work as a whole. We're eighth grade students and are probably going to never have a proper research if this doesn't work.


Bluetooth can't seem to find any devices or rahter be found Ubuntu 18.04 LTS

the output of dmesg | grep Blue:     [   26.323574] Bluetooth: Core ver 2.22 [   26.323590] Bluetooth: HCI device and connection manager initialized [   26.323593] Bluetooth: HCI socket layer initialized [   26.323596] Bluetooth: L2CAP socket layer initialized [   26.323601] Bluetooth: SCO socket layer initialized [   26.622067] Bluetooth: hci0: BCM: chip id 70 [   26.623062] Bluetooth: hci0: BCM: features 0x06 [   26.639063] Bluetooth: hci0: foola-X555LA [   26.639067] Bluetooth: hci0: BCM (001.001.011) build 0000 [   26.752454] Bluetooth: hci0: BCM: Patch brcm/BCM.hcd not found [   28.764082] Bluetooth: hci0: command 0x1003 tx timeout [   28.765089] Bluetooth: hci0: unexpected event for opcode 0x1003 [   37.549122] Bluetooth: BNEP (Ethernet Emulation) ver 1.3 [   37.549124] Bluetooth: BNEP filters: protocol multicast [   37.549127] Bluetooth: BNEP socket layer initialized [   40.604056] Bluetooth: hci0: command 0x1003 tx timeout [   40.605066] Bluetooth: hci0: unexpected event for opcode 0x1003 [   67.695736] Bluetooth: RFCOMM TTY layer initialized [   67.695745] Bluetooth: RFCOMM socket layer initialized [   67.695751] Bluetooth: RFCOMM ver 1.11 [  141.765044] Bluetooth: hci0: command 0x1003 tx timeout [  141.766235] Bluetooth: hci0: unexpected event for opcode 0x1003  The output of lspci -knn | grep Net -A2; lsusb: 03:00.0 Network controller [0280]: Broadcom Inc. and subsidiaries BCM43142 802.11b/g/n [14e4:4365] (rev 01)     Subsystem: Lite-On Communications Inc BCM43142 802.11b/g/n [11ad:6675]     Kernel driver in use: wl Bus 001 Device 002: ID 8087:8000 Intel Corp.  Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 002 Device 004: ID 04ca:2006 Lite-On Technology Corp. Broadcom BCM43142A0 Bluetooth Device Bus 002 Device 003: ID 0bda:57b5 Realtek Semiconductor Corp.  Bus 002 Device 002: ID 1b3f:2008 Generalplus Technology Inc.  Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub  Any help I would be very grateful!


For all Infinity Stones to be used, did it have to be a snap? Or was that Thanos' choice?

We all know Thanos specifically chose to snap to use all the Infinity Stones to wipe out half the universe. Even everyone else who gets an Infinity Gauntlet seems to have to snap in order to use all the Stones.  Did it have to be a snap in order to use all the Infinity Stones? Why wasn't it a clap? Or something else? I get Thanos chose to do a snap but if he had chosen to do a clap or something else, would it have worked?    The reason I'm not entirely sure is because Tony builds a gauntlet as well and he's not working off Thanos' gauntlet but he comes to the same conclusion-snap to use all Infinity Stones, granted this may have been easiest, but I'm still curious if it needed to be a snap or all gauntlets were just designed that way.    I'm specifically asking for lore on using all 6 stones. I know there's duplicates out there about how specifically the gauntlet is activated, but I'm asking if, in order to use all 6 infinity stones, a snap, by any party, whether it be Thanos, Hulk, Tony, other celestials, etc, is required on any gauntlet (or any device using all 6 stones), or if that was simply a choice by all parties that have used all 6 stones thus far.


Addressing research of faculty members in statement of purpose

Is it recommended to refer to research done by specific faculty members in a department in the SOP for graduate school admissions?   Does it not imply that you are interested in their research ONLY and thereby reduce your chances in case they don't have funding or had already other applicants/students who wanted to work with them?   If it can be beneficial, how can one address specific faculty research without limiting the audience of their application to them? (More specifically, consider physics PhD programs in US).


makes this point about emergencies: " When you’re budgeting each month for inevitable car repairs, the bill from the mechanic six months from now won’t be an emergency at all."  So... have multiple smaller funds, each for a large, but foreseeable, expense (auto repair, home repair, job loss, etc that money can be shifted in and out of if required) or One Big Fund for everything?  (I'm in the multiple smaller funds camp.)


I have the following code:  public class Test2 {     public static void main(String[] args) {          long ta, after, before;         Runtime rt;         rt=Runtime.getRuntime();         rt.gc();         NodoPrueba q=new NodoPrueba(1);          before=rt.freeMemory();         q=null;         rt.gc();         after=rt.freeMemory();         ta=after-before;         System.out.println("Before: "+before+"\nAfter: "+after);         System.out.println("\nDifference: "+ta);     }  }   Well, the class NodoPrueba only has an int attribute. But i have the following output:  Before: 127991976  After: 128673800  Difference: 681824  If the theory says that NodoPrueba class only takes 16 bytes on memory: 8 bytes from the object, 4 bytes for int and 4 bytes for padding (object's size is always a multiple of 8), where does the difference come from?


Executing a program (.exe) from a USB stick

I have a USB stick mounted (it appears in the output of lsblk) and contains an executable file: PortablePGP.exe which has executable permission and a file: autorun.inf  I do not know how to launch this program from Ubuntu 14.04.  If I click on it I get:      "STICK” contains software intended to be automatically started. Would you like to run it?   And when I click  run  I get:     Oops! There was a problem running this software. Unable to locate the program


A necessary and sufficient condition for $B \subset \ell^1$ to be compact

I want to show that:     For any $B\subset \ell^1$,   $B$ is compact if and only if $B$ is bounded, closed and satisfies   $$ \forall \epsilon>0, \; \exists N\in \mathbb{N}, \; \forall \{x_n\}_{n=1}^\infty \in B, \; \sum_{n=N}^\infty |x_n| < \epsilon. $$


How do i change just one side of a mirrored model?

I'm working on a model of a cat and i wanted to give it an earring on one side and a cut in the ear on the other. The problem is i've only created one half of the model and used the mirror modifier. so how will i be able to change one side?


I know about the famous identity $$ e^{ix}=\cos x + i\sin x $$ I have proved the above identity by comparing the Maclaurin series of $e^{ix}$,$\cos x$ and $\sin x$. But I want to know about other proofs of this identity. I have no idea about any such proofs. Any help would be appreciated.


Subject-verb agreement while talking about percent

Which one of the following two sentences is the correct sentence?   "20% of the participants believe that the world is flat." "20% of the participants believes that the world is flat."   What grammatical rules govern the choice of the correct sentence here?


Someone doesn't like an edit I suggested, and downvotes all of my questions

I am new to StackOverflow, and I edited few posts based on how I had seen many posts being written and one 'celeb' person here pointed out where I was wrong. I thanked him for letting me know, and that I was doing what I saw in good posts. But, I got downvotes on all my questions at the same time.   I don't think it s fair. (Not saying it because I lost reputation.) It just decreases credibility of my questions to anyone who sees it. This, to me, is just having advantage of being someone with high reputation and they can just go downvoting anyone because -1 reputation won't matter to them.


lim of integration of a non-negative function: $\lim\limits_{n\rightarrow\infty} \left[\int_a^b (f(x))^n \, dx\right]^\frac{1}{n} = M$

i'd like very much your help with this one :   given a positive function meaning $$ f(x) \geq 0 $$ and $f$  is continuous.  Let $$ M = \sup(f(x)) $$ where $x$ belongs to $[a,b]$.  How can i prove that  $$\lim_{n\rightarrow\infty} \left[\int_a^b (f(x))^n \, dx\right]^\frac{1}{n}  = M$$


Does anyone have a clever and direct proof of $\frac{|a-c|}{\sqrt{(1+a^2)(1+c^2)}}\leq\frac{|a-b|}{\sqrt{(1+a^2)(1+b^2)}}+\frac{|b-c|}{\sqrt{(1+b^2)(1+c^2)}}$


How to show that the determinant of this matrix is in a nice product factorization,

Show that  $$det \begin{bmatrix}         1 & 1 & \cdots &1 \\         \lambda_1 & \lambda_2 & \cdots &\lambda_n \\         \lambda^2_1 & \lambda^2_2 & \cdots &\lambda^2_n \\         \vdots & \vdots & \vdots & \vdots \\         \lambda^{n-1}_1 & \lambda^{n-1}_2 & \cdots &\lambda^{n-1}_n \\ \end{bmatrix} =\prod_{n\ge i>j\ge1}(λ_i−λ_j)$$  My work so far,  I am trying to use induction on $n$.  For the base case n=2, the claim is true, since we have $(\lambda_2 - \lambda_1)$.  I'm not sure how to carry out the inductive step.  Any hints or suggestions are welcome.    Thanks,


Installing Windows 10 (same product key) on a separate drive in case primary drive fails (multi-boot)

Current Setup:  My machine has four hard drives:  A 237GB SSD C: drive (almost full, nearly 4 years old) with Windows 10. I've got the original Windows 8 installation CD.  Storage Space (Z: drive), for important files. This Storage Space is comprised of two magnetic 1.8TB hard drives.  1.8TB magnetic drive (D:), currently unused and empty. Had some VM hard disk files there but I've moved them to my Storage Space (Z:) to make way for a new OS.  I have a Maximus VI Hero motherboard and UEFI bios.  Background:  I'm worried my C: drive will fail at some point. I need to get up and running again very quickly if this happens. I can't spend any time installing all the programs I need to do my job, especially if there's something urgent I need to deal with. (I realise that something else in my machine could fail, in which case I'd need a redundant workstation. Getting one soon.)  Goal:  I want to install Windows 10 on my spare D: drive. So if I lose the C: drive, I can boot Windows 10 on the D: drive, which will have all the programs I need installed and set up, good to go.  Main questions:  How do I do this?   Can I install Windows 10 on another drive using the same product key or do I need to buy another copy?  Related Questions:  I've dual booted Ubuntu and Windows on laptops before, but that was only one drive. Will I get something like a menu like Grub where I can choose which OS I want? I think I've seen a OS selection menu on Windows computers before.  Do I have to unplug or replug any cables before or after installation?   Will I be able to see the Storage Space (Z:) drive from the new Windows 10 OS?


Calculating AUC for one threshold in the continuous output is simple:  AUC = (TPR - FPR + 1) / 2;   What if I want to calculate AUC for multiple thresholds in continuous output of the classifier?


Why cant a readonly property be overrided with a read/write property in .net?

Conceptually it seems like a derived class should be able to override a readonly property with a read write property.  Why isn't this possible?  Public Class Base      Protected _name As String     Public Overridable ReadOnly Property Name() As String         Get             return _name         End Get     End Property  End Class  Public Class Derived     Inherits Base      Public Overrides Property Name() As String         Get             Return MyBase.Name         End Get         Set(ByVal value As String)             _name = value         End Set     End Property  End Class


How do I level up fast and get more shields and HP?

I have seen a video (                              ) of a guy who is at the same mission as me but of a much higher level as me (He is 25, I am 19) and has a TON more shields and HP than me.  I am pretty much always dying when I try to solo missions. When I am with a team, I have to let them do the mission while I sit in a corner.  Are there any tips to level up fast? Like.... kill tons of enemies, do side quests, etc.? Also, are there any ways to get more shields and HP?


Why "ain't I" and "aren't I" instead of "amn't I"?

Why do we say "ain't I" or "aren't I" instead of "amn't I"? What's the history of this usage? Are there any other similar patterns in English?  I'm guessing it has something to do with the dispreference of two consecutive nasal consonants, but a more authoritative answer would be great.


Does somebody of you know how to build a link as described in #9 in   I tried it this way  [title]   but the output ends with a "?" ... like me :-) The link to the node works, but the query/argument/contextual filter is missing in the url. How can I fix this?


Here's the scenario.  I have a remote application which is invoked from an HTTP callout.  In this callout, I am passing the session ID.  The application can then do its stuff without needing a username and password.  However, I want to be able to invoke the application from a scheduled job, and getsessionid() returns null in this case.  Is there any way around this?  I am trying very hard to avoid storing sfdc usernames and passwords on my remote server, and I want to avoid the hassle of using oAuth with all the complications of client secrets, etc.


Is there any package that can easily allow you to obfuscate a Latex->PDF generated document such that copy-paste is not longer possible and produces random letters for instance.  And if yes, is it possible to control which letters get modified?  Mailin


C++ program crashes on exit (binary files)

I made a program that writes a structure into a binary file, and then reads that binary file into a different variable. Writing into file and reading from it works fine, however the program crashes on exit.  I tried using the same variable for reading which works, but is not the solution I'm looking for. I want to know why the program crashes when I read structure from binary file into a different variable.  Here's the code:  #include <iostream> #include <fstream> #include <ctime> #include <stdlib.h>  using namespace std;  struct t_student{     string name;     string lastname;     int mark; };  int main(){     t_student student[30], student_read[30];     int n, i;     srand(time(0));      fstream dat("student.dat", ios::in | ios::out | ios::binary | ios::trunc);      cout << "Input number of students (up to 30): ";     cin >> n;     if(n > 30) n = 30;     cout << endl;      cin.ignore();     for(i = 0; i < n; i++){         cout << "Input first name: ";         getline(cin, student[i].name);          cout << "Input last name: ";         getline(cin, student[i].lastname);          student[i].mark = rand()%5+1;          cout << endl;          dat.write((char *) &student[i], sizeof(student[i]));     }      dat.clear();     dat.seekg(0);     i = 0;      while(!dat.eof()){         dat.read((char *) &student_read[i], sizeof(student_read[i]));         if(dat.eof()) break;         cout << endl << student_read[i].name << " " << student_read[i].lastname << "  -  " << student_read[i].mark;         i++;     }     dat.close();      cin.get();     //exit(0); }   As you might notice, I also added exit(0) function, which prevents the program from crashing, but I want to know why the program crashes in the first place.  Thanks for your help.


I'm quite new to JavaScript and I experiment a lot to get used to it. I trying to write JavaScript function that determinates if the date is from the past or future. It used datepicker form and somehow the if statement isn't working properly because whatever date I select it displays "Date from the future".   function selectDate() {     var d = new Date();     var day = d.getDate();     var month = (d.getMonth() +1);     var year = d.getFullYear();     var x=document.getElementById("dateSelection");  if (month.length < 2) month = '0' + month;     if (day.length < 2) day = '0' + day;  if (d > x) {     document.write("Date from the past" + "
");     document.write("Today is " +day+ "/" +month+ "/" +year+ ""); } else (d < x) {     document.write("Date from the future" + "
");     document.write("Today is " +day+ "/" +month+ "/" +year+ ""); }


Calculus proof - Possible application of a known proof

Let $a_n < c < b_n$ and $a_n, b_n → c$ as $n → ∞ $.    Suppose $ f : \mathbb{R} → \mathbb{R}  $ is continuous.     Show that (Possibly using similar proof to FTC...?)  $$  \lim_{n \to\infty }\frac{1}{{b_n - a_n}}\int_{{\,a_n}}^{{\,b_n}}{{f\left(x\right)\,dx}}         = f(c).$$


How can I contact a moderator in a private setting?

Where can I seek help if I need assistance with contributor-related questions? For the purposes of this question, "contributor" means "user who provides more answers than questions." I.e. how can I contact a moderator in a private setting?


What kind of insect can this be? This appears to be just a shell after and insect went through a metamorphosis process

What kind of insect can this be? This appears to be just a shell after an insect went through a metamorphosis process.


For example, in X session, I can use Ctrl-Alt-L to lock the screen, so it would ask for password to unlock and prevent somebody from messing with mine computer.  But if I have an open terminal session on one of the tty's (which I can access with Ctrl-Alt-F1, for example) - then it is not locked, and somebody can still use it to do some harm. Is there a way to 'lock' that command line (with some background processes running in it, maybe)?


Accidentally hit "toggle full screen", How do I exit?

I'm stuck in full screen in the node editor. Escape isn't working, and I have no menus and no idea how to leave except to quit Blender and reopen the program.


I'm learning Ubuntu and experimenting with things.  I noticed I couldnt create a directory within /sys  Is this a special directory or something? Are there other types of directories?  (I did a sudo -i and a chmod a+w /sys)


automator/applescript keypress repeating until released

script that will continue to send a keypress every 50ms. Here is a script I've used before and looking to create it in automator/applescript #IfWinActive World of Warcraft $r:: GetKeyState, state, r, P if state = D Loop { Send {r} Sleep, 50 return }


Integer values of $a$ for which $\lim_{x\rightarrow 1}\left(\frac{-ax+\sin (x-1)+a}{x+\sin (x-1)-1}\right)^{\frac{1-x}{1-\sqrt{x}}} = \frac{1}{4}$

Find Largest Integer values of $a$  for which $\displaystyle \lim_{x\rightarrow 1}\Bigg(\frac{-ax+\sin (x-1)+a}{x+\sin (x-1)-1}\Bigg)^{\frac{1-x}{1-\sqrt{x}}} = \frac{1}{4}\;,$ is   $\bf{My\; Solution::}$ We can write the above Limit as $\displaystyle \lim_{x\rightarrow 1}\Bigg(\frac{-a(x-1)+\sin(x-1)}{(x-1)+\sin(x-1)}\Bigg)^{1+\sqrt{x}} = \frac{1}{4}$  So $\displaystyle \lim_{x\rightarrow 1}\Bigg(\frac{-a+\frac{\sin(x-1)}{x-1}}{1+\frac{\sin (x-1)}{x-1}}\Bigg)^2 = \frac{1}{4}\Rightarrow \bigg(\frac{-a+1}{2}\bigg)^2 = \bigg(\frac{1}{2}\bigg)^2$  So We get $\displaystyle (-a+1) = \pm 1\Rightarrow a = 0$ or $a=2$  But answer given as $a = 0$ and I did not understand why it can not be $a = 2$  Please explain the reasoning behind it, Thanks


I would like to make star trails picture and I saw that one good way to do so is to take picture every like 30 seconds and them stack them all.  I have Sony a6500 camera. Is there a way to set this in camera as a setting or do I have to buy some hardware to do it?  If so, what is the name of such a device?  Thank you!


I'm trying to figure out a way to automatically select an option, based on a passed variable, that matches only the value of that option.         Font Type     <select id="options>         <option value="one">One</option>         <option value="two" selected>Two</option>         <option value="three">Three</option>     </select>   function loadSelect(userFont){     $('#options').find('option[value='+userFont+']').attr('selected', 'selected'); }  loadSelect(three);


They show up super far apart for some reason, I have 3 here but can only see one at a time because of this. Sorry if this isn't the right place for this, I didn't really know where else to report it.   Screenshot:        EDIT: Actually I think a video would explain this better:


Show that $ \overline \lim\limits_{n \rightarrow \infty}\left(\frac{1+a_{n+1}}{a_{n}}\right)^{n} \geq \mathrm{e} $

Show that $$  \overline \lim\limits_{n \rightarrow \infty}\left(\frac{1+a_{n+1}}{a_{n}}\right)^{n} \geq \mathrm{e}  $$ For any sequence $\{a_n\}$ with positive terms, and that this estimate cannot be improved.  I found this problem in "Mathematical Analysis I" of Zorich, just Google Books and turn to page 149 of the preview. I believe this problem is somehow incorrectly stated (since I can't solve it :) ) , so I asked for sure.   Thanks.


"WAN: disabled" when connecting router to cable modem

I am trying to set up internet access with a Linksys WRT54G router (DD-WRT, set as a AP) and a  which uses . The problem is that the router can’t connect to the Internet via the cable modem. At the top of the router management page, the router always reports:     WAN: disabled   The signal lights on the cable modem are all OK (blue) except the last one (internet), which is a blinking orange/yellow. The computer can see the router management page, but not the cable modem page (192.168.100.1).  If I connect the router directly to the computer, then internet connection works fine, and I can see the modem management page (192.168.100.1). I have used this router in the past few years to get Internet connection without a problem.  All above is with wired connections.  Has anyone had similar issues and does anyone know a solution?


No reviews after 7 months of paper submission

I have submitted a paper to IEEE transactions on knowledge and data engineering (TKDE). Until now, it has been 7 months and the status of my paper is still "Under Review". It has stayed in the same status from the first day of the submission. I have sent an email to the admin of the journal, and she replied to me that the paper was being processed. I have waited more than 1 month without any update.   Has anyone experienced the same situation? What should I do? Many thanks.


The answer of this function is returned into the main function of the program, and that works fine. The issue is that any value where the cosine should be 0, it turns out to give a weird irrational number (something like 1.30431912*10^-13). So, 90, 450, and so on, all turn out irrational answers. What's the matter?    float cosineDegrees() {         string i;         double iDouble;          cout << "Give me a number to find the value of degrees in. ";         getline(cin, i);          iDouble = stod(i);          double PI = 3.14159265359;          float answer = cos((PI/180)*iDouble);          return answer;       }


shellscript is having trouble finding a file

I have a shellscript that is having trouble finding a file. The text file exists so I don't understand what the issue is.   #!/bin/ksh goodmain $1 | sed -e '1,/mmxxaa/d'  $ ls -l total 1364 -rwxr-xr-x. 1 s student  94563 Apr 23 23:55 a.out -rwxrwxrwx. 1 s student     19 Apr 28 17:13 boo -rw-r--r--. 1 s student     89 Apr 24 00:58 cookies -rw-r--r--. 1 s student   1622 Dec  6 23:49 doc -rw-r--r--. 1 s student    148 Apr 23 16:14 textfile -rw-r--r--. 1 s student 597061 Apr 23 23:56 fn -rwxr-xr-x. 1 s student  94563 Apr 28 16:56 goodmain -rw-r--r--. 1 s student 427993 Apr 23 23:47 main.c -rw-r--r--. 1 s student 145256 Apr 24 00:40 main.o -rw-r--r--. 1 s student     72 Apr 28 16:53 makefile -rwxrwxrwx. 1 s student     46 Apr 28 17:24 p4 $ ./p4 textfile ./p4: line 2: goodmain: not found


Can I use my Windows 7 license in a dual-boot configuration?

Possible Duplicate:          I've purchased a retail license of Windows 7 Ultimate for my machine at home.  I'm thinking of creating a dual-boot install:   64-bit install for work apps (need the RAM for virtual machines and RAMDisk) 32-bit install for entertainment apps (Media Centre, games, etc)   How does retail licensing work in such situations? Can I activate the same license on both installations?  Edit:  I would like to add that I want to have separate partitions for work and play.


If x = 0.999... (a) -> 10x=9.999... -> 10x-x=(9.999...)-(0.999...)  -> 9x = 9 -> x = 9/9 = 1 (b)   x = 0.999 (a) = 1 (b) ?  So... what is the right explanation for this occur? I know that exists a tiny error somewhere... I think that the subtraction of the repeating decimal is incorrect, because the principle of infinity. That's it? Am I right?