$f(m^2 + f(n)) = f(m)^2 + n$ for all natural numbers

Find all functions such that $$ f(m^2 + f(n)) = f(m)^2 + n$$ for all natural numbers (1,2,3,4,..)  I have been stuck on this problem.   I have tried to set f(1) = k, however, did not make any progress.


My latex document consists of hundreds of TeX files that are loaded by the main file using the \input command. I need to submit the TeX code to the publisher of a scientific journal for publishing. Is there a way of running the original TeX file, loading all the \input's and produce one TeX file with the code loaded by \input in the file?


This question had come in jee advanced 2015. Give a hint to solve it.


SciFi story from before 1976 that involves multiple dimensions

Sometime in 1976 I read part of a book and never finished it.  The book or short story involved the following.  Multi-dimensional worlds. Possibly multiple duplicate worlds. Our world causes conflict by sending things to another dimension, unknowingly causing damage. The other dimension then retaliates. I remember something about damage to some kind of theater.  Any ideas who the author could be and the work's name?


Show that $A \subset B \implies A \cap B = A$

I am trying to show that:  $$A \subset B \implies A \cap B = A$$  So far I got:  $$A \subset B$$ $$A \cap B \subset A$$ $$A \cap B \subset B$$ $$A \cap B \subset A \subset B$$


The  gives the following rules for long jumping:  Jumping Your Strength determines how far you can jump. Long Jump. When you make a long jump, you cover a number of feet up to your Strength score if you move at least 10 feet on foot immediately before the jump. When you make a standing long jump, you can leap only half that distance. Either way, each foot you clear on the jump costs a foot of movement. This rule assumes that the height of your jump doesn't matter, such as a jump across a stream or chasm. At your DM's option, you must succeed on a DC 10 Strength (Athletics) check to clear a low obstacle (no taller than a quarter of the jump's distance), such as a hedge or low wall. Otherwise, you hit it. When you land in difficult terrain, you must succeed on a DC 10 Dexterity (Acrobatics) check to land on your feet. Otherwise, you land prone.  The section on Movement and Position also gives the following:  On your turn, you can move a distance up to your speed. You can use as much or as little of your speed as you like on your turn, following the rules here. Your movement can include jumping, climbing, and swimming. These different modes of movement can be combined with walking, or they can constitute your entire move. However you're moving, you deduct the distance of each part of your move from your speed until it is used up or until you are done moving. Breaking Up Your Move You can break up your movement on your turn, using some of your speed before and after your action. For example, if you have a speed of 30 feet, you can move 10 feet, take your action, and then move 20 feet.  related:


What lenses have the most human eyelike images

I have heard wide lenses make your head inflated which isnt good for portraits like the telephoto which deinflates your head.  So If I use 35mm prime on full frame. Does it mean I will get perfect human vision? Our vision is rather "elliptical diagonal" but how close an 35mm on full frame will be to the human vision whatever angle of view or distortions? How close will it be to the putting my head to the where lens is when I shoot it?  I know two eyes give sideways wider angle of view while one eye reduces it and I would like comparisions to the both open eye situations.  I also know there is always the fact that cameras sensors use nothing but the 3:2 aspect ratio.  Altough my question looks like an simple angle of vision thing. I also don't want the lens .  If you try to 50mm then the image is too zoomed (at least according to this comment by rackandboneman "I would assume something like a 12mm equivalent to be closer to what we perceive as our field of vision :) and if you try bigger angle of view lenses then the stretching effect starts to happen and there is always the barrel distortion stuff.  So what lenses gives the most eye like vision on full frame? How should I crop the photos for human aspect ratio? At least in a single camera setup and not a two lens 3D setup which I suppose be more realistic.


I've managed to set up a binary tree and can print the contents as it inserts the nodes. However, when I use a method to traverse the tree, I can create a traversal, producing multiple single arrayLists, but when I try to populate a single arrayList with the traversal I get a NullPointerException and I'm not sure why.  The original that works.      @Override public List<T> traverse() {      List<T> traversal = new ArrayList<T>();      populateTraversalList(this,traversal);      if (this.isEmpty()) {         return null;      } else {         traversal.add(this.getValue());         root.getLeft().traverse();         root.getRight().traverse();     }      System.out.println(traversal.toString());      return traversal; }   Produces the output. When given an Integer binary tree produced from an array of {0, 1, 2, 4 , 3, 5, 6, 7}.  [3] [7] [6] [5] [4] [2] [1] [0]   But when I try to neaten it up it gets nullptrs.   @Override public List<T> traverse() {      List<T> traversal = new ArrayList<T>();      populateTraversalList(this,traversal);      System.out.println(traversal.toString());      return traversal; }  private void populateTraversalList(BinaryTree<T> searchTree, List<T> traversalList) {     if (this.isEmpty()) {         return;     } else {         traversalList.add(getValue());         populateTraversalList((BinaryTree<T>) searchTree.getLeft(), traversalList);         populateTraversalList((BinaryTree<T>) searchTree.getRight(), traversalList);      } }   It seems to specifically object to the searchTree.getLeft() line, but from my understanding I should be passing on the same instance into the first parameter. Thank you in advance.


How to apply javascripts to element wich has been overwrited by jquery .html()

Here I have an example:     $('#key').on('click', function(){   $('.task').html("<button id='key'>Button</button>"+Date()); }) <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <div class='task'>   <button id='key'>Button</button> </div>     How I can apply javascript for overwriting element and get different time for each button press?


How do I set up my Yongnuo RF-603II trigger and Yongnuo YN-568EX flash?

I have a Nikon D5000 with one Yongnuo RF-603II trigger. How can I use my Yongnuo YN-568EX flash as an external flash? What settings do I use?


Is there such a thing as "pangram for phonemes"?

English has a lot of pangrams, which are short sentences that use every letter of the alphabet at least once.  has several examples. But is there a similar thing that is designed to use (almost) every phoneme of the English language?  I know it would be nearly impossible to come up with something that uses all of them (and it is mostly likely going to be a paragraph, and not a sentence, given the amount of phonemes), but still, my question remains: is there such a thing? (And what is it called?)


I attempted a solution using this version of Taylor's Theorem, \begin{align*} |f(d) - P_n(d)| &= \left| \frac{f^{n+1}(t)}{(n+1)!} \right| |d-c|^{n+1} \\ |f(d) - f(c) - f'(c)(d-c)| &= \left| \frac{f''(t)}{2} \right| |d-c|^2 \end{align*} Letting $d=1$ and $c=1/2$ and using the triangle inequality, I get $$ \frac{|f''(t)|}{4} - \frac{|f(d)-f(c)|}{|d-c|} \geq -|f'(c)| $$  The negative sign on the RHS is throwing me off because otherwise I could easily achieve the desired result. Am I attempting using the wrong theorem or are there any glaring mistakes in my process?


I have created a sample Django application with multiple models within it and populated data.  Now, I need to add a new column to one of the models?  Here are my concerns?   What will happen if I do syncdb after adding a column to the model , will it just alter the table and add the new column? Or will it create a new table after deleting all the columns?   Is there any better way to tackle this issue?


Is there a quick and easy way to pronounce "W" letter?

I mean, there is a well known 'substitution' for number "0" with 'ou' sound. Like, '107' in military communications will be pronounced as 'one-ou-seven'. Is there similar kind of substitution for letter "W", say, in aforementioned military comms? Some way that allows to pronounce it much quicker?


Running two PHP versions (5.3 & 5.2) at the same time

I have read this topic:   There, the issue is handling two different generations of PHP (PHP 4 vs PHP 5), but what I need is to make all but one of my server accounts work under 5.3 and just a single domain under 5.2.  I cannot make this through Apache models, and the answer from  does not apply since in my case I can't use a different port - this is a regular website  on the same server.


How to prove the continuity of the function of several at $(0,0)$

How to verify the continuity of the following function at $(0,0)$ :  \begin{cases}f(x,y)=\cfrac{x^3}{x^2+y^2}& \text{if } (x,y)\neq (0,0)\\ f(0,0)=0\end{cases}


I have trouble getting the form of citations I need. Once I cite I want to see authors' names and not numbers. The unconventional thing is that I have to use the documentclass elsarticle (This is editor's request), which always produce numbers. Here is it what I have  \documentclass{elsarticle} \usepackage{natbib} \usepackage[colorlinks=true,linkcolor=black, citecolor=blue, urlcolor=blue]{hyperref}  \begin{document}  \bibliographystyle{plainnat} \bibliography{references}  \end{document}   Can someone help me on this?  Here's an expanded MWE.  \documentclass{elsarticle} \usepackage{amssymb} \usepackage{graphicx} \usepackage{amsmath, mathtools} \usepackage{natbib} \usepackage[colorlinks=true,linkcolor=black, citecolor=blue, urlcolor=blue]{hyperref} \usepackage{changes} \usepackage{appendix} \usepackage{filecontents} \usepackage{multirow} \usepackage{booktabs}    \begin{document}  \section{The Model}  The main environment modifies that of \cite{Diamond1965}, into two main dimensions  \newpage  \bibliographystyle{elsarticle-harv} \bibliography{references}    \end{document}


$$\frac{\sin A - \cos A}{\sin A+\cos A}=\frac{X}{Y}$$ Then prove that $X^2 + Y^2 = 2$. Answer : $\frac{\sin A-\cos A}{\sin A+\cos A}=\frac{x}{y}$ $\implies x=k(\sin A-\cos A)$ and           $y=k(\sin A+\cos A)$.   Squaring on both sides and adding   $x^2+y^2=k^2(\sin A-\cos A)^2+k^2(\sin A+\cos A)^2$  $\implies x^2+y^2=k^2[\sin^2A+\cos^2A-2\sin A\cos A+\sin^2A+\cos^2A+2\sin A\cos A]$  $\implies x^2+y^2=2 k^2$ But how can eliminate k.means by what logic we can say k=+1 or -1. Please suggest. Thanks.


I'm new to Blender and I'm following this cloud tutorial but the person's mapping node is completely different, with inputs I don't have such as this "scale" input. Why is this? Can I change it? Mine:  Theirs:


28 dominoes lying in one direction what is the last one?

Peter with a standard double six set lays 28 dominoes in one direction - what will be the last number on the end on then of the last domino?   Suppose he plays in both directions and discovers that he can use all the dominoes that he has available but Ann announces she hid one from before he started - which one will it be?   I have the answer 6 for the first part but anyone have a clue of the second part because in a pack there is 28 and if she hid one it makes it 29 this makes no sense to me any one make sense of it?


I'm looking for metaphors (non-jocular) with the same meaning as "Trojan Horse" - "A person or thing intended to undermine or destroy from within."


This problem is from Romanian G.M. and although it is very short, it is also (I think) very hard. Let $x, y, z$ real non-negative numbers such that $x+y+z=3$. Prove that   $$27 \leq (x^2+2)(y^2+2)(z^2+2) \leq 44 $$  I didn't succeed in any of the inequalities, I only managed to find the equality cases ($x=y=z=1$ for the first one and one of them $3$ and the others $0$). Any hint/idea/solution is welcome.


How can I launch a GUI program from a terminal but close the terminal once it's launched?

I like to start GUI programs from the terminal, e.g. emacs myfile.txt. But doing that leaves a terminal window open with that process, so now there are two windows for me to keep track of. And if I close the terminal window, the GUI program closes.   I know I can run exec cmd, where cmd is the command I'm trying to run, and that closes the terminal window after the program completes. But I want to close the terminal window after the command is launched. Is there a way to do that?


I have already beat Uncharted 3 on Normal and I am trying to do it on Hard. I have gotten to the final boss fight with Talbot and nothing I do seems to work. I can only attack him at the very beginning of the fight. After about 30 seconds of fighting, every time I press square to attack him he puts me in the hold where he holds my arm behind my back and tries to stab me. I press circle as fast and as many times as possible but Nate never bites his arm. Talbot always just throws me out of the hold. This just happens over and over again for sometimes longer than 10 minutes or until I get frustrated and start over. I must be doing something wrong or there is a glitch in the game. Please help me out?


How do I make sure my computer doesn't reset without asking me first?

I am perfectly happy with my computer letting me know when there are updates that need to be installed and resetting is necessary.  I want it to continue doing that.  I do not, however, want it to do so by informing me that if I don't stop it from restarting in the next X minutes it will do so automatically, so that if I happen to be away from the computer when the 10 minute warning pops up, I lose any unsaved work.  I want restarting to be an opt-in feature, not an opt-out feature.  My computer should never restart without me approving it.  Is there a way to change my Microsoft Windows 7 settings to that it does not restart without my approval?  (I don't know the tags here so well.  Please re-tag as appropriate.)


I used  to export my auxiliary files into a different directory. Basically i just add -aux-directory=build in Options -> Configure -> Commands and added the build folder into Options -> Configure -> Build -> Build Options -> Additional Search Paths -> Log. This succesfully generates all the auxilliary files in the build folder and it's also possible to generate the pdf. Unfortunately biber has a problem with this setup:  Prozess gestartet: biber.exe "MyFile" INFO - This is Biber 1.7 INFO - Logfile is 'MyFile.blg' ERROR - Cannot find control file 'MyFile.bcf'! - did you pass the "backend=biber" option to BibLaTeX? INFO - ERRORS: 1  I guess i have to specify the correct path for biber somewhere in Texstudio. Does anyone know where i have to update the path?  someone had similar problems. Also i'm not sure if the solution of   applies to my situation.


I've been reading about the difference between a python constructor (__new__) vs. an initializer (__init__) on .  Given that __new__ is used to create class instances, and __init__ is used to customise those instances.   Why do most examples & working code of python classes built only with __init__?  Examples  and  (search "5. Classes")


What's the point of the axiom of extensionality?

The axiom of extensionality is:  ${\forall}a({\forall}b({\forall}c(((c{\in}a){\iff}(c{\in}b)){\iff}(a=b))))$  The definition of $(P{\iff}Q)$ is:  ${\lnot}((P{\implies}Q){\implies}({\lnot}(Q{\implies}P)))$  or, in other words  $(P{\land}Q){\lor}({\lnot}P{\land}{\lnot}Q)$  In the case of the statement $((c{\in}a){\iff}(c{\in}b))$, this leads us to two options: $((c{\in}a){\land}(c{\in}b))$ and $({\lnot}(c{\in}a){\land}{\lnot}(c{\in}b))$. So far nothing weird. Now, let's see all the possible results of the axiom.  1.$((c{\in}a){\land}(c{\in}b)){\land}(a=b)$ 2.${\lnot}((c{\in}a){\land}(c{\in}b)){\land}{\lnot}(a=b)$ 3.$({\lnot}(c{\in}a){\land}{\lnot}(c{\in}b)){\land}(a=b)$ 4.${\lnot}({\lnot}(c{\in}a){\land}{\lnot}(c{\in}b)){\land}{\lnot}(a=b)$  Coincidentally, they are also all possible statements regarding the statements $((c{\in}a){\land}(c{\in}b))$ and $(a=b)$: both parts are true, the first part is true and the other is false, the second part is true and the first is false and neither is true. The axiom seems not to state anything new, because rephrased it's just produces a list of all possible options regarding the two parts of the statement. Worse, it doesn't seem to say anything about equality, since it allows for $a=b$ with both $(c{\in}a){\land}(c{\in}b)$ and ${\lnot}((c{\in}a){\land}(c{\in}b))$. So, what is the point of this axiom? And in what way does it say anything about equality?


Let $X, Y, Z$ be independent and $N(1,1).$ Find the probability that $X + Y ≥ 3Z$ using convolution.

I did the following: Let $W=X+Y-3Z,$ then we have that   $$W\sim N(1+1-3,1+1+9)=N(-1,11).$$  so  $$P(X+Y\ge3Z)=P(W\ge 0)=1-P(W\le 0)=1-F_W(0)=1-\Phi\left(\frac{1}{\sqrt{11}}\right)\approx \\ \approx 1-0.618 = 0.382.$$  However, I'm in the chapter treating convolution. How can I solve this problem using this approach instead?


How to do a print screen or capture an area of the screen

Is there an equivalent of the Window's Print Screen + Paste (or better yet the Mac OS Cmd+Shift+4, Space) in Gnome?


VirtualBox: Windows 7 says it's not genuine

I've set up a Windows 7 guest machine under Windows 7 using oracle virtualbox 4.2. This Windows Guest has its own product key which corresponds to the boxed set I purchased for the sole purpose of running it in virtualbox. A few months ago I backed up my Windows 7 virtual box virtual disk image on an external hard drive. Now that the Windows 7 started to malfunction, I deleted it, and copied it back from my external hard drive.  However now it's telling me that the version of windows is not genuine. How can it be. There is nothing else using the same product key, unless someone hacked into my backup folders and stole the protuct key from there and used it on a machine of their own.  Thanks.


Differential Notation Magic in Integration by u-Substitution

I'm really confused now. I always thought that the differential notation $\frac{df}{dx}$ was just that, a notation.  But somehow when doing integration by u-substitution I'm told that you can turn something like this $\frac{du}{dx} = 2x\;$ into this $\;du = 2x\ dx$.  But how is that even possible? I understand that the notation comes from the fact that $\frac{du}{dx}$ actually means the limit of the difference in $u$ over the difference in $x$, with $\Delta x$ approaching $0$.  $$u'(x) = \frac{du}{dx} = \frac{du(x)}{dx} = \lim_{\Delta x\to 0} \frac{u(x+\Delta x)\ -\ u(x)}{(x+\Delta x) - x} = \lim_{\Delta x\to 0} \frac{u(x+\Delta x)\ -\ u(x)}{\Delta x}$$  So if $\frac{df}{dx}$ is just a notation for the limit mentioned above, then what is the underlying argument to say that you can treat $\frac{du}{dx}$ as if it were an actual fraction?  Appreciate the help =)


Let $X$ be a normed linear space with a finite dimensional dual $X^*$. How do I prove X is also finite dimensional?


I have 2 classes:  1. DeviceData 2. MinDeviceData  DeviceData class contains 15 fields and methods, while MinDeviceData contains only one field - int count and some methods.  In my code, I am trying to do a performance test on 100k operations of fromString from string to this class. I expect the time result to be consistent, but every time I run the test - I get different result.  Why?  This is my code:  @Test     public void checkClasses() throws IOException, InterruptedException {         String pkt = "BIG JSON OBJECT HERE";         for (int x = 0; x <= 5; x++) {             TimeUnit.SECONDS.sleep(5);              /**              * Check NO FIF              */             ObjectMapper om = new ObjectMapper();             HashMap hm = new HashMap<>();              int cycle = 100000;             long startTime = System.nanoTime();             for (int i = 0; i <= cycle; i++) {                 DeviceData.fromString(pkt, om, hm);             }             long containsDuration = (System.nanoTime() - startTime);  //divide by 1000000 to get milliseconds.             long object = containsDuration/cycle;             System.out.println("--- Duration NIF: " + containsDuration +",per pkt in nano:" + object );              TimeUnit.SECONDS.sleep(5);              /**              * Check FIF              */             Gson gson = new Gson();             long fifStartTime = System.nanoTime();             for (int i = 0; i <= cycle; i++) {                 DeviceDataMin.fromString(pkt, gson);             }             long regexDuration = (System.nanoTime() - fifStartTime);  //divide by 1000000 to get milliseconds.             long fif = regexDuration/cycle;             System.out.println("--- Duration FIF: " + regexDuration +",per pkt in nano:" + fif );              System.out.println("DIFF : " + (100 - (double) ((double)fif * 100/object)));         }     }   Test Result (output):  --- Duration NIF: 676214146,per pkt in nano:6762 --- Duration FIF: 563609001,per pkt in nano:5636 DIFF : 16.651878142561372 --- Duration NIF: 415484807,per pkt in nano:4154 --- Duration FIF: 392932554,per pkt in nano:3929 DIFF : 5.416466056812709 --- Duration NIF: 377752426,per pkt in nano:3777 --- Duration FIF: 389876068,per pkt in nano:3898 DIFF : -3.2036007413290974 --- Duration NIF: 349583684,per pkt in nano:3495 --- Duration FIF: 392007947,per pkt in nano:3920 DIFF : -12.160228898426325 --- Duration NIF: 470443379,per pkt in nano:4704 --- Duration FIF: 368536421,per pkt in nano:3685 DIFF : 21.6624149659864 --- Duration NIF: 346816168,per pkt in nano:3468 --- Duration FIF: 354205262,per pkt in nano:3542 DIFF : -2.1337946943483246


Workaround for Android 4.4 not being able to write to SD cards?

Yesterday I upgraded my Samsung Galaxy S4 to Android 4.4 KitKat and had the bad surprise that it cannot write to my SD card anymore... I know this problem is widely documented everywhere, but has any workaround been found for it yet? (Other than removing the card physically from the phone and opening it on my PC) Also, because of the KNOX flag I can't downgrade to 4.3...  (PS: Rooted or not, it makes no difference)


Is 3+1 spacetime as privileged as is claimed?

I've often heard the argument that having 3 spatial dimensions is very special. Such arguments are invariably based on certain assumptions that do not appear to be justifiable at all, at least to me. There is a  on Wikipedia.  For example, a common argument for why >3 dimensions is too many is that the gravitational law cannot result in stable orbital motion. A common argument for <3 dimensions being too few is that one cannot have a gastrointestinal tract, or more generally, a hole that doesn't split an organism into two.  Am I being overly skeptical in thinking that while the force of gravity may not be able to hold objects in stable orbits, there most certainly exist sets of physical laws in higher dimensions which result in formation of stable structures at all scales? It may be utterly different to our universe, but who said a 4D universe must be the same as ours with one extra dimension?  Similarly, isn't it very easy to conceive of a 2D universe in which organisms can feed despite not having any holes, or not falling apart despite having them? For example, being held together by attractive forces, or allowing certain fundamental objects of a universe to interpenetrate, and thus enter a region of the body in which they become utilized. Or, conceive of a universe so incomprehensibly different to ours that feeding is unnecessary, and self-aware structures form through completely different processes.  While I realise that this is sort of a metaphysical question, is 3+1 dimensions really widely acknowledged to be particularly privileged by respected physicists?


Categorized views in past flags (helpful/declined/disputed)

I like to know it when I do or see something wrong. So I really like our flagging history (x moderator attention flags, y deemed helpful, z declined, etc.)  I specifically find the declined / disputed flags interesting, because one can learn from his faults. However, now you have to scroll through all your good flags, to see your few bad flags.   Can't we have a function to select only the helpful, only the declined or only the disputed? I also consider  to be a very good idea: sort on flag type ('not an answer', 'spam', etc.) too.


I looked at an answer for a question and I don't know how they came to this conclusion.  $(k+1)!-1 + (k+1)!(k+1) = (k+2)! - 1$  What are the stepps behind it?


How can i remove howdy from ubuntu 20.04

I'm trying to remove howdy windows hello style login, how can we do it?


What would be the value of $\sum\limits_{n=0}^\infty \frac{1}{an^2+bn+c}$

I would like to evaluate the sum  $$\sum_{n=0}^\infty \frac{1}{an^2+bn+c}$$  Here is my attempt:    Letting    $$f(z)=\frac{1}{az^2+bz+c}$$  The poles of $f(z)$ are located at   $$z_0 = \frac{-b+\sqrt{b^2-4ac}}{2a}$$  and  $$z_1 = \frac{-b-\sqrt{b^2-4ac}}{2a}$$  Then  $$ b_0=\operatorname*{Res}_{z=z_0}\,\pi \cot (\pi z)f(z)= \lim_{z \to z_0} \frac{(z-z_0)\pi\cot (\pi z)}{az^2+bz+c}= \lim_{z \to z_0} \frac{\pi\cot (\pi z)+(z_0-z)\pi^2\csc^2 (\pi z)}{2az+b} $$  Using L'Hopital's rule. Continuing, we have the limit is  $$ \lim_{z \to z_0} \frac{\pi\cot (\pi z)+(z_0-z)\pi^2\csc^2 (\pi z)}{2az+b}= \frac{\pi\cot (\pi z_0)}{2az_0+b} $$  For $z_0 \ne 0$  Similarly, we find  $$b_1=\operatorname*{Res}_{z=z_1}\,\pi \cot (\pi z)f(z)=\frac{\pi\cot (\pi z_1)}{2az_1+b}$$  Then   $$\sum_{n=-\infty}^\infty \frac{1}{an^2+bn+c} = -(b_0+b_1)=\\ -\pi\left( \frac{\cot (\pi z_0)}{2az_0+b} + \frac{\cot (\pi z_1)}{2az_1+b}\right)=  -\pi\left( \frac{\cot (\pi z_0)}{\sqrt{b^2-4ac}} + \frac{\cot (\pi z_1)}{-\sqrt{b^2-4ac}}\right)= \frac{-\pi(\cot (\pi z_0)-\cot (\pi z_1))}{\sqrt{b^2-4ac}}= \frac{\pi(\cot (\pi z_1)-\cot (\pi z_0))}{\sqrt{b^2-4ac}} $$  Then we have  $$\sum_{n=0}^\infty \frac{1}{an^2+bn+c} = \frac{\pi(\cot (\pi z_1)-\cot (\pi z_0))}{2\sqrt{b^2-4ac}}$$    Is this correct?  I feel like I made a mistake somewhere.  Could someone correct me?  Is there an easier way to evaluate this sum?


I have tried several approaches to solve my problem but unfortunately none successful yet. I can not find documentation mentioning how to solve this particular case. My problem is that I am using a subfigure in beamer and I am trying to create multiple \ref points before the \label appear in the same figure. When compiling the .tex document only one reference point appears and the rest are appearing as ??. Is there any possible solution to my problem?  EDIT: The code I'm using  \documentclass[xcolor=pdftex,dvipsnames,table]{beamer} \usepackage[english]{babel} \usepackage{hyperref} \usepackage{cleveref} \usepackage{caption} \usepackage{subcaption}  \mode<presentation> \setbeamertemplate{caption}[numbered]  \begin{document} \begin{frame}  \begin{columns}[t]  \begin{column}[T]{5cm}  \begin{itemize}  \item<+-| alert@+> 1~\autoref{1}  \item<+-| alert@+> 2~\autoref{2} etc  \end{itemize}  \end{column}  \begin{column}[T]{5cm}  \begin{figure}  \only<1>{\begin{subfigure}[b]{1.0\linewidth}           \caption{sub caption 1}           \label{1}           \includegraphics[width=7.0cm,height=5cm]{fig 1}           \end{subfigure} }  \only<2>{\begin{subfigure}[b]{1.0\linewidth}           \caption{sub caption 2}           \label{2}           \includegraphics[width=5.5cm,height=5cm]{fig 2}           \end{subfigure} } \caption{main}  \protect\label{3}  \end{figure}  \end{column}  \end{columns}  \end{frame} \end{document}


How many keys does the Playfair Cipher have?

I was just studying the Playfair cipher and from what I've understood, it is just a slightly better version of a Caesar cipher, in that it isn't actually mono-alphabetic but rather the 'digrams' are mono-alphabetic. I believe that since it offers a larger combination i.e 26*26=676 digrams, it is better than a Caesar Cipher which would give us a maximum of twenty-six keys. So does this mean that the Playfair Cipher have 676 keys including the duplicate or is it larger than that ?


How can I prove that $xy\leq x^2+y^2$ for all $x,y\in\mathbb{R}$ ?


How do I make a block only be placed on a certain block when crafted?

I'm trying to make a map but I'm stuck on a command When a player crafts an item I want to let it only be placed on a block, like when a player crafts a crafting table, the command block will make so it's only placeable on gravel. I seen it in other maps. How do I do it? Also I want to make it so certain tools and break some blocks If anyone knows please tell me. P.S. not the /give command


How do I determine the correct position for my bicycle seat?

I have been suffering from IT band problems on my outer knee, which I'm pretty sure were caused by raising my seat height too much. I raised the seat on the advice of a friend who said that a higher seat gives more power in each stroke.  By trial and error over several months I have found a (lower) seat height that seems to be acceptable, but I still get occasional twinges if I cycle a lot, so I suspect it's still not quite right.  Is there a well-understood way to correctly determine the best height for a bicycle seat? Are there factors other than seat height that are important to consider?


Identity Element and Identity Properties

Learning more abstract algebra, really not the most enjoyable of subjects, as nothing seems all that clear cut, but here goes anyway.  I have a set $\mathbb Q = \{{p \over q} : p,q\in \mathbb Z \text{  and  } q \neq 0\}$ which is the set of rational numbers and for $x,y\in \mathbb Q$ defined the binary operation $*$ on $\mathbb Q$ by $$x*y = x + y + xy.$$  The pair $(\mathbb Q, * )$  has an identity element. Find the identity element then verify the identity properties for $(\mathbb Q,*)$.  Where do I begin?


In my list i have a object with null property and i want to remove this object but while checking in if condition its ConcurrentModificationException

My code is as follows  for(User user: userList){             if(user.getName()==null){                 userList.remove(user);             }         }   here i am checking for null value of name property but it trows null pointer exception on checking the condition  StackTrace  java.util.ConcurrentModificationException     at java.util.ArrayList$Itr.checkForComodification(Unknown Source)     at java.util.ArrayList$Itr.next(Unknown Source)     at in.net.usit.dbu.web.transformation.TransformationViewModel.initializeData(TransformationViewModel.java:106)     at in.net.usit.dbu.web.transformation.TransformationViewModel.init(TransformationViewModel.java:91)     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)     at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)     at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)     at java.lang.reflect.Method.invoke(Unknown Source)     at org.zkoss.bind.impl.ParamCall.call(ParamCall.java:111)     at org.zkoss.bind.impl.AbstractAnnotatedMethodInvoker.invokeMethod(AbstractAnnotatedMethodInvoker.java:87)     at org.zkoss.bind.BindComposer.doAfterCompose(BindComposer.java:170)     at org.zkoss.zk.ui.impl.UiEngineImpl.doAfterCompose(UiEngineImpl.java:534)     at org.zkoss.zk.ui.impl.UiEngineImpl.execCreateChild0(UiEngineImpl.java:836)     at org.zkoss.zk.ui.impl.UiEngineImpl.execCreateChild(UiEngineImpl.java:782)     at org.zkoss.zk.ui.impl.UiEngineImpl.execCreate0(UiEngineImpl.java:691)     at org.zkoss.zk.ui.impl.UiEngineImpl.execCreateChild(UiEngineImpl.java:753)     at org.zkoss.zk.ui.impl.UiEngineImpl.execCreate0(UiEngineImpl.java:713)     at org.zkoss.zk.ui.impl.UiEngineImpl.execCreate(UiEngineImpl.java:655)     at org.zkoss.zk.ui.impl.UiEngineImpl.createComponents(UiEngineImpl.java:1036)     at org.zkoss.zk.ui.impl.AbstractExecution.createComponents0(AbstractExecution.java:246)     at org.zkoss.zk.ui.impl.AbstractExecution.createComponents(AbstractExecution.java:238)     at org.zkoss.zul.Include.afterCompose(Include.java:450)     at org.zkoss.zul.Include.onAfterCompose(Include.java:434)     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)     at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)     at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)     at java.lang.reflect.Method.invoke(Unknown Source)     at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:2725)     at org.zkoss.zk.ui.AbstractComponent.service(AbstractComponent.java:2655)     at org.zkoss.zk.ui.impl.EventProcessor.process(EventProcessor.java:136)     at org.zkoss.zk.ui.impl.UiEngineImpl.processEvent(UiEngineImpl.java:1721)     at org.zkoss.zk.ui.impl.UiEngineImpl.process(UiEngineImpl.java:1506)     at org.zkoss.zk.ui.impl.UiEngineImpl.execUpdate(UiEngineImpl.java:1216)     at org.zkoss.zk.au.http.DHtmlUpdateServlet.process(DHtmlUpdateServlet.java:601)     at org.zkoss.zk.au.http.DHtmlUpdateServlet.doGet(DHtmlUpdateServlet.java:483)     at org.zkoss.zk.au.http.DHtmlUpdateServlet.doPost(DHtmlUpdateServlet.java:492)     at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)   this is the stacktrace i don't how to find the solution please help me with that


After submitting a revised manuscript (moderate revision was requested), what are the steps followed?

I have submitted a manuscript to a reputed journal. After 2 months of peer review process, the response was “moderate revision has been requested” and they told me that the new version is required within 1 month. After making the necessary adjustments, I have resubmitted the revised manuscript back on the 14th of October 2017. On the 21st of October the status changed from “with editor” to “under review”. To date (16th December) the status is “under review”. In fact, I had made some readings about late reviews, I found that reviews are normally due 14 days after the invitation is accepted by the reviewer. Should I worry about manuscript rejection? Thanks in advance for your help


How to prove that the random variables $X$ and $X^2$ are not independent?

Given that the probability density function of random variable $X$ is given by $$f(X)=\begin{cases} \dfrac12,&\text{for} -1\le x\le1\\0,&\text{otherwise}. \end{cases}$$ I tried it using expectations but it turned out that $\Bbb E(X^3)=\Bbb E(X)\Bbb E(X^2)$. What should I do next?


Proving $\sqrt{2}$ is irrational: why $ q = p - \frac{p^2 -2}{p+2}$

I've just begun self-studying Rubin's Principals of Mathematical Analysis.   I'm having difficulty understanding a specific line in example 1.1 (proving $\sqrt{2}$ is irrational). Specifically, I'm trying to understand how they arrive at the following:  $ q = p - \frac{p^2 -2}{p+2}$  Here is the proof up to that point:  Let A be the set of all positive rationals p such that $p^2 < 2$ and let B consist of all positive rationals p such that $p^2 > 2$. We shall show that A contains no largest number and B contains no smallest number.   More explicitly, for every p in A we can find a rational q in A such that $p < q$, and for every p in B we can find a rational q in B such that $q < p$.    Any help would be much appreciated.


My windows 7 boot very slow (stage when windows desktop appear), it need something about 10 minutes, to start working normal. Do you know any software to profile/analyze windows booting time ? I want to check which applications/services takes the most booting time and why.


ubuntu 15.04 alongside windows 10 dual boot

I have sony-vaio E-series model SVE14A15FAP. it was windows7 pre installed but I upgraded to windows10. used for some time and I want to use it alongside ubuntu 15.04, but after a successful installation of Ubuntu 15.04, the boot option is not showing up.it boot straight to windows giving me no option.  Please help me


Is it possible to have things orbit around us?

Since humans are not large in mass, do we exert enough gravitational force for a small object to orbit around us? (Assuming that the only gravitational force acting on the object is from the human). Using Newton's law of gravity and using myself as the human mass, I exert a 10^-8 force on a 1 kg object .5 meter away, but I am not sure if even this small of a force will be acceptable. What is the baseline "force" between two objects for 1 to orbit another?  Edit: I am not sure if this is a SpaceExchange question.


Why do we use the objective case pronoun "me" in "He can watch me clean the car"?

He can watch me clean the car.   In this sentence, the pronoun me is used as the object of the verb watch. But isn't me also acting as the subject of the verb 'clean' and therefore should be I instead? Obviously 'he can watch me clean the car' sounds correct but why is it this way?  Is there a rule that governs this?   Reopen note  This question has been linked to this question here:      However, that question is clearly about whether to use an infinitive or a gerund-participle form after the verb hear. This question is as described above. It is about the function of the pronoun me in sentences like the one described.


How to display year-based Gmail labels in reverse chronological order?

I set up year-based labels in Gmail to archive old mails -- e.g. year 2001, year 2002, ... year 2013, year 2014, etc.  The problem is that Gmail displays the labels in the alphabetical order, which, in turn sorts these year-based labels in chronological order.  But as with anyone else, I need to look up recent emails more often than decade-old emails, which means that the label I need to reach most often will sit at the bottom of the year-based labels.  Would there be a clever way to display these year-based labels in reverse alphabetical order (i.e. reverse chronological order)?


I've heard that 'play piano' is OK in American usage. Is that true? What I learned so far is 'play the piano'. As long as it comes to the instruments, we usually "play the (instrument)". Is that correct?


Deleting Grease Pencil and grease pencil usage showing up in the Timeline

In the hierarchy I have "GPencil and GP_Layer". I would like to delete this from the hierarchy. But mainly, every time I use the grease pencil, Blender puts a lime-green line in the timeline. I would like to get rid of those too, or at least hide them in the Timeline.


Reading  a few people have assumed that Dumbledore understands Parseltongue but can't speak it. Where is the evidence in the books (or movies) of this?  I've read all the books a few time and the only thing that comes to mind is the memory at Little Hangleton where some of the Gaunts speak it. Unless I'm remembering poorly it isn't indicated if Dumbledore understands them - he lets Harry know that Harry can understand it (as a way of letting Harry know that it's Parseltongue and not English since Harry hears it as English).


Uses of saxon genitive with the word Google as the owner

I would like to know which one of these expressions is the most correct and why?     Google´s car      The car of Google   When I refer to the driverless car Google has invented.


App crashing when starting new activity on button click

I'm sorry for asking such a basic question, but I haven't found anything that could help me with this issue. I'm trying to do something as simple as starting a new activity through a button click, but my application crashes whenever I click that button. Here is my code:  Button aboutButton = (Button)findViewById(R.id.aboutButton);     aboutButton.setOnClickListener(new View.OnClickListener()     {         @Override         public void onClick(View view)         {             Intent intent = new Intent(MainActivity.this, About.class);             startActivity(intent);         }     });   This code is inside a function, which is in turn inside the onCreate function. I've already tried putting this code straight into the onCreate function, but I got the same result. Could you please tell me what I have done wrong?  PS.: My target activity is already declared at the manifest.  Error log :   java.lang.RuntimeException: Unable to start activity ComponentInfo{com.ukdev.TestApp/com.ukdev.TestApp.About}: java.lang.NullPointerException


Traductions: are lips movements changed for every language?

If I watch The Simpsons in French for example then the lips movements match with the oral traduction.  Question: In general, are lips movements in animated films/shows modified to match traductions in languages different from the original one?  This seems like a lot of work to me, but I don't see how there could be a perfect match if it wasn't done.


I must use this patch http callout. Is any one has idea?    I get error      "Invalid HTTP method: PATCH"   Exception.  In our project need to use this callout.  Is any other way to update the record from salesforce to goformz record?  HttpRequest req= new HttpRequest();         req.setMethod('PATCH');         req.setHeader('Content-Type','application/json');         String username = 'username123@email.com';         String password = 'password123';          Blob headerValue = Blob.valueOf(username + ':' + password);         String authorizationHeader = 'Basic ' + EncodingUtil.base64Encode(headerValue);         req.setHeader('Authorization', authorizationHeader);         req.setBody('{"name": "DE-111","fields": {"7f91803f-fed6-41cb-b506-a62d01500de0": { "text": "Test Street1111"  } }}');         Http http = new Http();          String url = 'https://api.goformz.com/v2/formz/4bc24f7f-bac8-4632-97b6-a640005becb8';         req.setEndpoint(url);         HttpResponse res = http.send(req);


How to differentiate between 2 identical 1TB hard drives?

I have a system with Linux Mint and Windows 10 installed on it. My Windows 10 side has the boot drive on a 60gb partition of a 120gb SSD, with the data drive on a 1TB HDD (this has all my data on it). My Mint side also has the boot drive on a 60gb partition of a 120gb SSD, with the /home partition on a different 1TB HDD (the data on this one can be deleted). I need to replace Mint with Ubuntu, but I want to make sure I don't overwrite my data on Windows 10 data drive. Last time I did this  I guessed and picked the wrong one and lost some files, and I don't want that to happen again. Is there a way I can differentiate between the two hard drives?


I have two questions :  First, I wanted to hide Ubuntu’s side-bar, so I set the settings in appearance to 'autohide'. The side bar did indeed disappear but when I roll over the left side, the side bar don't appear again. So, I am using a virtual box. Can it explain the fact that this bar doesn't show again when it is set to autohide.   Second, assuming I wouldn't be able to come over the problem, I pined to the dock every element of the sidebar, except the dash home. Is it possible either to pin it in the dock or to launch it from the terminal ?


Bluetooth is not working on my laptop Ubuntu 18.04.4 LTS

Linux pc 4.15.0-76-generic is show on but not working. Dell inspiron 1521. How to solve this bluetooth problem?  02:00.0 Network controller [0280]: Broadcom Inc. and subsidiaries BCM43142 802.11b/g/n [14e4:4365] (rev 01)     Subsystem: Dell Wireless 1704 802.11n + BT 4.0 [1028:0016]     Kernel driver in use: wl     Kernel modules: bcma, wl Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 005: ID 0c45:64ad Microdia  Bus 001 Device 004: ID 0bda:0129 Realtek Semiconductor Corp. RTS5129 Card Reader Controller Bus 001 Device 003: ID 0a5c:21d7 Broadcom Corp. BCM43142 Bluetooth 4.0 Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 003 Device 002: ID 046d:c535 Logitech, Inc.  Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub [   22.026377] Bluetooth: Core ver 2.22 [   22.026400] Bluetooth: HCI device and connection manager initialized [   22.026404] Bluetooth: HCI socket layer initialized [   22.026406] Bluetooth: L2CAP socket layer initialized [   22.026412] Bluetooth: SCO socket layer initialized [   24.113880] Bluetooth: hci0: BCM: chip id 70 [   24.114825] Bluetooth: hci0: BCM: features 0x06 [   24.130858] Bluetooth: hci0: himanshu-pc [   24.130863] Bluetooth: hci0: BCM (001.001.011) build 0000 [   24.336532] bluetooth hci0: Direct firmware load for brcm/BCM.hcd failed with error -2 [   24.336536] Bluetooth: hci0: BCM: Patch brcm/BCM.hcd not found [   26.364031] Bluetooth: hci0: command 0x1003 tx timeout [   26.364883] Bluetooth: hci0: unexpected event for opcode 0x1003 [   35.978595] Bluetooth: BNEP (Ethernet Emulation) ver 1.3 [   35.978597] Bluetooth: BNEP filters: protocol multicast [   35.978601] Bluetooth: BNEP socket layer initialized [   38.684072] Bluetooth: hci0: command 0x1003 tx timeout [   38.685760] Bluetooth: hci0: unexpected event for opcode 0x1003 [  100.076586] Bluetooth: RFCOMM TTY layer initialized [  100.076592] Bluetooth: RFCOMM socket layer initialized [  100.076601] Bluetooth: RFCOMM ver 1.11 [  166.099911] Bluetooth: hci0: command 0x1003 tx timeout [  166.100849] Bluetooth: hci0: unexpected event for opcode 0x1003


I would like items in a list to have a hanging indent (that is, for all lines after the first to be indented by a space or more),  but the traditional \hangindent command doesn't work for this.  \documentclass{article}  \begin{document} \hangindent=1cm This line of text has a hanging indent that looks fine, as long as it is outside a list environment. \begin{enumerate} \item \hangindent=1cm This line is inside a list environment and doesn't have a hanging indent- how can I add one? \end{enumerate} \end{document}     How can I add a hanging indent within a list?


I'm trying to deep copy a huge Json content. But, unfortunately, It still referencing the object.  The elobj content:  {   "children": [     {       "children": [         {           "children": [],           "cfg": {             "blockName": "",             "binding": {               "cbind": {},               "cBindAttrTexts": {},               "cBindAttr": {}             },             "layout": {},             "include": {}           },           "frontCfg": {             "pseudoClasses": {               "selectedClass": "None",               "InlineOrSelector": "Inline",               "selectedSelector": "New"             }           },           "natifChildren": {},           "cssConfig": {},           "htmlConfig": {             "class": {},             "attr": {}           },           "CBindTexts": [],           "CBindAttrTexts": {},           "CBindAttr": {},           "cssValues": {},           "customAttrs": {},           "type": "text",           "content": "A paragraph"         }       ],       "cfg": {         "blockName": "",         "binding": {           "cbind": {},           "cBindAttrTexts": {},           "cBindAttr": {},           "cBind": {             "entity": "Entity2",             "field": "column2"           }         },         "layout": {},         "include": {},         "js": {}       },       "frontCfg": {         "pseudoClasses": {           "selectedClass": "None",           "InlineOrSelector": "Inline",           "selectedSelector": "New"         }       },       "natifChildren": {},       "cssConfig": {         "width": [           "auto",           [             "1266",             "px"           ]         ],         "height": [           "auto",           [             "20",             "px"           ]         ],         "backgroundSize": [           "auto auto",           [             0,             "px"           ],           [             0,             "px"           ]         ],         "backgroundPosition": [           "custom",           [             "0",             "%"           ],           [             "0",             "%"           ]         ]       },       "htmlConfig": {         "class": {},         "attr": {}       },       "CBindTexts": [],       "CBindAttrTexts": {},       "CBindAttr": {},       "cssValues": {},       "customAttrs": {},       "tag": "p",       "type": "p"     }   ],   "cfg": {     "blockName": "",     "binding": {       "cbind": {},       "cBindAttrTexts": {},       "cBindAttr": {},       "cBind": {}     },     "layout": {},     "include": {},     "js": {}   },   "frontCfg": {     "pseudoClasses": {       "selectedClass": "None",       "InlineOrSelector": "Inline",       "selectedSelector": "New"     }   },   "natifChildren": {},   "cssConfig": {     "width": [       "auto",       [         "1266",         "px"       ]     ],     "height": [       "auto",       [         "30",         "px"       ]     ],     "backgroundSize": [       "auto auto",       [         0,         "px"       ],       [         0,         "px"       ]     ],     "backgroundPosition": [       "custom",       [         "0",         "%"       ],       [         "0",         "%"       ]     ]   },   "htmlConfig": {     "class": {},     "attr": {}   },   "CBindTexts": [],   "CBindAttrTexts": {},   "CBindAttr": {},   "cssValues": {},   "customAttrs": {},   "tag": "div",   "type": "div" }   The cloning code:  var elobj = elem.myApp().getElementObject(); var elemObject = $.extend(true, {}, elobj); elemObject.children[0].cfg.binding.cBind.field = "id"; console.log(elobj)   After I cloned the elobj to elemObject. When I change the field to "id", field from the variable elobj should have the original value which is "column2". But both changed to "id".


Time required to traverse a tunnel through the centre of a planet

There is a tunnel along the diameter of a uniform planet of mass $M$ and radius $R$. A particle is projected toward the centre with speed equal to the orbital speed of a satellite in a circular orbit just grazing the surface of the planet. Determine the time after which the particle reaches the the other end of the tunnel for the first time.    I don't know why is it that the required time is half the time of revolution in an orbit of radius $R$. I know that the time period is independent of the eccentricity of the elliptical orbit, but here the degenerate ellipse along which the particle is projected continues outside the planet too


Function works normally alone but doesn't work properly when calling several times. Python

So the question is pretty strange. I wrote an algorithm to move contents of any list (array) by a given number of digits to the left.  DIGS = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 ]  # move functions def move(arr):     this = arr     first = this[0]     for b in range(len(this) - 1):         this[b] = this[b + 1]     this[-1] = first     return this  def move_with_step(arr, step):     this_arr = arr     for a in range(step):         this_arr = move(arr)     return this_arr   And, obviously, when typing print(move_with_step(DIGS, 5) will give us the same DIGS array but twisted. It will be something like [ 5, 6, 7... 3, 4 ]. You get the idea. And in this case it works. BUT...     The problem is: if I'd put this same call into the for loop like below or just one after another, it will give me wrong results which is kinda strange because it should'n modify DIGS itself and why is that happening IDK.   So this code  for a in range(1, 6):     print(move_with_step(DIGS, a))   Returns this  [1, 2, 3, 4, 5, 6, 7, 8, 9, 0] [3, 4, 5, 6, 7, 8, 9, 0, 1, 2] [6, 7, 8, 9, 0, 1, 2, 3, 4, 5] [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] [5, 6, 7, 8, 9, 0, 1, 2, 3, 4]   in the console. Which is crazy and totally wrong. Why is that?


FILEZILLA not working after upgrade from ubuntu 15.10 to ubuntu 16.04

I have upgraded to Ubuntu 16.04 from 15.10 (x64 version) and now I am unable to run FileZilla.  There is some hard drive activity and then nothing.  When I open a terminal and type "Filezilla" I get the following error:   Reading locale option from /home/james/.filezilla/filezilla.xml (filezilla:5532): Gtk-CRITICAL **: IA__gtk_widget_set_size_request: assertion 'height >= -1' failed (filezilla:5532): Gtk-CRITICAL **: IA__gtk_widget_set_size_request: assertion 'width >= -1' failed (filezilla:5532): Gtk-CRITICAL **: IA__gtk_widget_set_size_request: assertion 'height >= -1' failed (filezilla:5532): Gtk-CRITICAL **: IA__gtk_widget_set_size_request: assertion 'width >= -1' failed (filezilla:5532): Gtk-CRITICAL **: IA__gtk_widget_set_size_request: assertion 'width >= -1' failed (filezilla:5532): Gtk-CRITICAL **: IA__gtk_widget_set_size_request: assertion 'height >= -1' failed (filezilla:5532): Gtk-CRITICAL **: IA__gtk_widget_set_size_request: assertion 'width >= -1' failed Segmentation fault (core dumped)   I have checked my system log and it has this line:  May  2 21:56:55 JamesPC kernel: [ 3133.290205] filezilla[5532]: segfault at 140 ip 00007f8a3152dbc6 sp 00007ffda52e17e0 error 4 in libwx_gtk2u_core-3.0.so.0.2.0[7f8a3102d000+5f9000]


How to take String JSON values into HashMap

I have an org.bson.Document that I can convert into a JSON:  for (Document dc : list) {         String doc = dc.toJson();     }   And the String looks like:  { "_id": "C:\\Users\\santi\\Desktop\\2010-documents.biased\\99\\2010-99-086.html",   "data": {         "german": 1,          "metadata": 1,          "inform": 20,          "almanac": 1,          etc etc         }  }   I'm stucked at figuring how to access to the "data" field and get all the key-value values and store them into a HashMap or Map. I thought about spliting the array and getting some substrings etc but doesn't seem like a good way.


I can teach you how to bottle fame, brew glory, even stopper death    -- Chapter 8, The potion master, Harry Potter and the Sorcerer's Stone   This quote give Snape's almost an almighty aura. Do we know at some moment to what he may refer here?  “Brew glory” might refer to “Felix Felicis” but I am clueless for the other two. It is also possible that at this time, JKR did not thought to much abour the means Snape would use to achieve what he said.


Sequence of tenses when we express certainty

I beg your pardon but I have a doubt about this sentence:     "They failed to believe their eyes as they realized their world is   just an experiment"   So, if we are following a correct sequence of tense, we should use the past tense in both verbs. However, in the second clause we express certainty so the present simple ("is") appears appropriate. Is that correct? Thanks!


Doing a debug_backtrace() - White Screen when putting it in drupal_set_message()

I currently have the following code in my drupal_set_message()  1778 function drupal_set_message($message = NULL, $type = 'status', $repeat = TRUE) { 1779   if ($message) { 1780    if ($type == 'error') { 1781        $message .= ' '. print_r(debug_backtrace(), 1) .' '; 1782    } 1783 1784     if (!isset($_SESSION['messages'][$type])) { 1785       $_SESSION['messages'][$type] = array(); 1786     } 1787 1788     if ($repeat || !in_array($message, $_SESSION['messages'][$type])) { 1789       $_SESSION['messages'][$type][] = $message; 1790     } 1791 1792     // Mark this page as being uncacheable. 1793     drupal_page_is_cacheable(FALSE); 1794   } 1795 1796   // Messages not set when DB connection fails. 1797   return isset($_SESSION['messages']) ? $_SESSION['messages'] : NULL; 1798 }   I'm trying to do a debug_backtrace on this function to find out which module is causing my error. Whenever i reload the page, I only get a white screen of death.  What could i be doing wrong here? Or what other quick methods like this can I find a module that is causing issues?


LaTex compiler refuses to start a new pdf page

I am writing a journal article using the following settings:   \documentclass[letterpaper, 12pt]{article} \usepackage[margin=1in]{geometry} \usepackage{setspace} \doublespacing \usepackage{secdot} \usepackage{mathptmx}  \begin{document}      {\fontfamily{ptm}\selectfont  \title{This title}  \maketitle  \begin{abstract}  I examine  \end{abstract}   {\small\bfseries Keywords} Hello  \pagenumbering{gobble} \pagebreak  \pagenumbering{arabic}  \section{Introduction} \section{Introduction} \section{Introduction} \section{Introduction} \section{Introduction} \section{Introduction} \section{Conclusion} \section{References} \section{Conclusion} \section{References} \appendix \section*{Appendix}  } \end{document}   Everything was going well until my TexStudio stopped creating a new page automatically. Note that my Page number 2 is now above my Section Headings. If I enter more text, it disappears under page 2 and no page 3 is automatically created. Please help!   I tried to search on many forums if this error can be resolved. I also repasted my code on Overleaf.com compiler and I see the same problem - so there is no issue with my TexStudio compiler! There is a problem with my code as 'page breaking' is not happening automatically.


How does a Terminator's living tissue actually "live"?

It is basic/common knowledge that our skin/flesh requires proteins etc carried by blood and pumped by a heart to travel around the body to live.  Its possible that Terminator's have blood underneath their living tissue, we certainlly have seen blood on Terminator's through out the universe cannon, but have not seen they have some sort of a heart to pump this blood around and they certainly do not eat.  So the question is: How does a terminators living tissue actually live?   Is there some EU information how it technically works?


Can you use "team" in plural or singular only?

Is it correct to say "The development team are seeing a new trend", when you're certain that the team consists of several members? Or, is the word team strictly singular in any context?


Problem with double value with Expansion in java , I was trying to add two double values but not giving accuracy

The given values are   double double1 = 1.0814449990040142E7;  double double2 = 7.0164302885665664E17;  result is double1  + double2 = 7.016430288674711E17  in Java   Manually calculated value is 701643028867471089  Can anyone resolve my issue.


Let $G$ be a group with order $p$ a prime number. Show $G$ is cyclic.  I know that if $G$ is a cyclic group and if $|G|=n$, then $G\cong\mathbb{Z}_n$. But I don't where to go from there.  Any help/hints would be welcome. ^_^


Examples of infinite groups such that all their respective elements are of finite order.

I am in need of examples of infinite groups such that all their respective elements are of finite order.


I'm looking for this novel (or maybe a series of books?). I remember that technology began failing all over the world. Some people began transforming into different types of mythical creatures, like sprites, demons, etc. There was a band of about four travelers that were trying to make it to Chicago, since that seemed to be at the center of the issue. The story line frequently shifted the point of view in each new chapter. I vaguely recall a final battle in Chicago with an enormous and powerful demon creature. I think this demon used to be a corporate lawyer or big business guy before his transformation. I believe I read this in the early/mid 2000s, and was likely published around that time because of the types of tech used and failing in the story. Although it bears some surface similarity to the TV show, Revolution, they aren’t comparable in plot or characters.


How to connect mobile broadband using terminal?

I configured new-mobile-broadband connection. I know that I can connect by clicking as following:    But I want to connect manually to that mobile broadband by using terminal.  How to do with terminal command?


Modify this formula : $R/I \cong \phi[R]/\phi[I]$

Let $R$ be a ring and $I$ an ideal of $R$, and let $\phi : R\longrightarrow R'$ be a ring homomorphism.   Studying by myself, I have a conjecture the following: $$R/I \cong \phi[R]/\phi[I].$$ This formula is such a beautiful result. But, I found the error when the homomorphism is not one-to-one. So, I want to modify this formula as possible.   My trial is the following.  First, assume the homomorphism $\phi$ is one-to-one. But, this revision may be useless because its assumption is too strong.  Second, in order to use the first isomorphism theorem, if $\psi : R\longrightarrow \phi[R]/\phi[I]$ is a canonical homomorphism, then the modification of our formula is $R/\ker\psi \cong \phi[R]/\phi[I]$.   Except the above modifications, do you have another modification? Please let me know!


HOW is electric field inside a conductor placed in an external field zero?

Lets assume that there is an external field +E acting on a conducting plate from left to right. Due to this, some electrons will drift from right to left to cancel out this electric field inside the conductor. But since some electrons have moved to the left surface of the sheet, there should(?) be an accumulation of positive charge on the right side of the sheet which should also have an electric field of its own (will this accumulation of positive charge on the right side of the sheet be equal in magnitude to the charge due to the accumulation of electrons on the left side ?). So how is the net electric field ever getting zero because there will always be some positive charge in the conductor which will have a field of its own. If maybe this field attracts some electrons to neutralize it, there will always be some positive charge due to this attraction of electrons to have a field of its own. Please tell me what exactly happens inside the conductor since my above idea is probably wrong.  I know that  "its electrostatics so no field can move and thus field should be zero" but I want to know HOW this happens and no other question addresses this "HOW" or my concern about the positive charge build up (if there is any kind of buildup)   ^This answer talks about the electrons neutralizing a positive field by drifting to one side but then it loses context to what I want to know by talking about the impact of the external field strength (I want to know the impact of the field created by the positive charge inside the conductor, if there is any)   ^The answer in this thread talks about the negative charge moving (as i have already mentioned above) but doesn't tell whether there is any kind of positive charge build up on the opposite side and the field due to it (because the electrons have moved to the other side)


Suppose $Y$ be an ordered set in the order topology. Let $f, g: X \to Y$ be continuous. How to show that the set $\{x| f(x) \leq g(x)\}$ is closed?  This is a excercise from munkres. Maybe trying to show that the set $f(\{x| f(x) > g(x)\})$ is open is suffice. But I could not figure out the connection between this set and the continuity of the two functions.Could you give a hint?  Thanks.


How to integrate $\int_{0}^{2\pi}\log{|a-e^{i\theta}|}d\theta$?

I need to calculate the integral $$\frac{1}{2\pi}\int_{0}^{2\pi}\log{|a-e^{i\theta}|}d\theta$$  When $|a|> 1$, I can show it equals $\log|a|$. But I failed to handle the situation when $|a|\leqslant 1$. I know it should be $0$.  I tried to use $\log(a-z)$, but when $|a|\leqslant 1$, such $\log$ can not be defined. So anyone can help?    Updated: the second situation should be $|a|<1$.


In the rank nullity theorem for $T \colon V \to W$, $V$ is finite dimensional. What if $V$ is infinite dimensional?

In the Sylvester rank nullity theorem, $T \colon V \to W$ is a linear transformation and $V$ is finite dimensional. What if $V$ is infinite dimensional?   This was actually asked before on this site, but I’m not satisfied with the answers. Please give me a sketch of a proof how this is true in infinite dimensions, and please give me an example for it.


F6 key issues error: Record file not found

I try to press the F6 key and in the YouTube tutorials those who make the video pressing them all go well, but not me :(


How do I solve the exponential equation?

I have this equation:  $3^x + 4^x = 5^x$, according to , $x <= 2$, so the answer is $2$.  But how can I get to the result through an elementary algebraic procedure?  I have tried many things, but I have not come up with any concrete results, arriving only at:  First try, $log(3^x+4^x) = 3log5$  Second try, $(\frac{3}{5})^x + (\frac{4}{5})^x = 1$  I have also tried to search several programs, such as symbolab, mathway, etc. But, they have not been able to solve it, the only program that has given me an answer is wolframAlpha, but I can not visualize it step by step, thanks in advance.


What does “a couple” mean to you, and what does “a few” mean to you?  Is there a proper way to use these words?  It was striking to hear that “a couple” meant two (2) to someone.  My reaction was, “how/why do you make a short word longer by adding an extra syllable to just say ‘two?’”  I think Few: 2-3, Couple 4-6, Several 7+.  What are your thoughts?


If $T$ is a linear functional then $T$ is an open map

Let $$T be a non-zero linear functional from a normed linear space $X$ to $K$($\mathbb{R}$ or $\mathbb{C}$). Prove that $T$ maps open sets to open sets. My Attempt: Since $T$ is a non-zero linear functional it is onto. Now if I can prove that there exists a $\delta>0$ s.t. for every $y\in K$ there exists $x\in X$ with $\|x\|<\delta \|y\|$ and $Tx=y$, then we are done. But I am not getting how to do it. Thanks in advance.


Integer part of a positive real number exists and is unique

I was looking through Tao's Analysis I and came across this problem     Prove that $\forall x\in \mathbb R^+,\exists!N\in\mathbb {N}$ s.t. $N\leqslant x<N+1$   I came up with a solution but I used the well-ordering of the natural numbers, which apparently is only treated later on in the book. I am wondering if anyone can suggest how else I should prove it.  My proof: Let $x\in\mathbb R^+$.  Consider the set $S=\{n\in\mathbb N\mid n>x\}$. Then $S\subseteq \mathbb N$. Also $S\neq \emptyset$ by the Archimedean property ($\forall x,\varepsilon\in \mathbb R^+,\exists N\in\mathbb N$ s.t. $N\varepsilon>x$, with $\varepsilon=1$ in this case).  Then by the well-ordering of $\mathbb N$ there exists a minimum $n_0\in S$, which is unique, $\forall n\in S, n_0\leqslant n $. We have $n_0>x>0$ so $n_0\geqslant 1$ which means that $n_0-1$ is defined.  Now $n_0-1\leqslant x$, for if $n_0-1>x$ then $n_0$ wouldn't be the minimal element of $S$.  So take $N=n_0-1$ and we have found a unique (by the uniqueness of the minimal element of $S$) $N\in\mathbb N$ s.t. $N\leqslant x<N+1$. Q.E.D.  As I said earlier, my question is if someone could suggest another method I could use to prove the statement. Furthermore I would be grateful if you point out errors that you find in my proof.


Assasination Missions. How to invest money and make more money?

I have finished the main story and all my main characters ended up making close to 31 Million apiece from the Big one. I only finished one Assassination mission so far which was the Hotel assassination, but i didn't play others because people advised me to reserve the Assassination missions to the end of the game.  This is all i know currently that these assassination missions end up killing some company's CEO and trick is to invest on their opposite number.   I want to know what others used to make money from these missions like if i should invest all my money on opposite company's stock from all the characters and play the mission and another question being once i complete the mission when is a good time to sell the stocks again?


I would like to use the  package to format date(time) ranges.  For example, \DTMdaterange{2017-08-05}{2017-09-10} would output 2017-08-05/09-10 in ISO format, or something like August 5 to September 10, 2017 in US English.  I looked into implementing it myself, but find it a bit hard.  Is there any package that already includes this functionality aside from ?  I thought  might be a good candidate, but cannot find anything useful (I am mostly interested in formatting dates; times are not necessary).


If $X$ and $Y$ are independent random variables, with $Z = \min(X,Y),$ prove that $Z^2\sim\chi^2(1),$

Let $X \sim N (0, 1)$ and $Y ∼ N (0, 1)$ be two independent random variables, and define $Z = \min(X, Y )$. Prove that $Z^2\sim\chi^2(1),$ i.e. Chi-Squared with degree of freedom $1.$  I found the density functions of $X$ and $Y,$ as they are normally distributed. How would one use the fact that $Z = \min(X,Y)$ to answer the question? Thanks!


How can the symmetric group $S_3$ be represented as $\{1, x, x^2, y, xy, x^2y\}$

On page 42 in his book Algebra, Artin begins describing the symmetric group $S_3$. He claims the six elements of the group are $\{1,x,x^2,y,xy,x^2y\}$. I don't understand how he got these elements. How did he get these 6 elements?


Can a top level domain provider close their business?

If I buy one of those weird top level domains, like example.pizza, or example.love, etc, I understand that there is a private company owning each of them, which save the records and redirect using their own servers. (obligated to ICANN) Question is, if this company closed, or go out of business, or just decide they don't want to provide service anymore, what happens to all the websites with this extension? In other words, is it safe to buy one of those top level domains? also, can it reduce speed if they don't operate well enough?


Backup and restore all application to fresh ubuntu install

I want to backup all my installed applications so that I can use them in fresh installation of Ubuntu (12.04 as of now) later.   only picks up .deb ( at /var/cache/apt/archives)  but I have installed packages by downloading from the internet. What I want to backup all my applications and configurations so that I do not have to go through the hurdle again.    and  are useful but I guess solution to my problem is simpler than this.  Why can't I backup all everything within the root (/) and then when ubuntu is installed fresh just copy all the files to the new / and then do sudo apt-get update and update grub and etc/fstab?  Please help this newbie to understand this.


How can I scrape only word data from a website?

I want to download all the word content from a particular website. Save the results in MS Word, Excel or Notepad and check which words are repeated most often and how many times.


Make div that fill all height of page left from another div only with CSS

I'm trying to make page with normal div #header and scrollable div #content, so my #content fill all the height left from the #header, even if #header changes his own height.  I tried several options and that is this is my last one . But the flaw of this option is that I need to change top property of #content (utilize JavaScript) if height of the #header changes.  Is there any solution to achive my goals only with css?  html {     height: 100%; } body {     height: 100%;     margin: 0;     position: relative; } #header {     background-color: tan; } #content {     overflow: auto;     background-color: teal;     position: absolute;     bottom: 0;     top: 20px; }
     Test header

     Test content


javascript sum with parseFloat giving wronge value

function myFunction() {     var c = parseFloat("10.81") +parseFloat("10.00"); alert(c); }   //output is 20.810000000000002 why?


What do we call "down" in this sentence?

"I have fallen down." I thought adjective at first, but it isn't really an adjective right? Because it doesn't really modify me, it modifies how I fell? So it is modifying the verb.


Does focal length change when I adjust the focus?

When I adjust the focus of my camera, in general, does this affect the focal length? I have heard that it does.


How to kill an app in iPhone using objective C

In my app  I am having a continuous communication with TCP server , now if   server sends a command to close the app, i want to close the app completely   and when user taps the app again, it should start with Application launch method itself.   I have tried using exit(0) in the code, using this application goes into background.But it doesn't kill the app. How can i do that?


Extracting a range of data from a python list

I have a list of unicode values.  To the best of my knowledge I can use list[starting location:length to select] to select a range of values from a list, right?  I have a list of 78 unicode values, which are not all unique.  When I select a range of 5 values beginning from the 0 position in the list (example: list[0:5]) the correct values are returned.  However, when I try to select a range of values that do not begin at the 0 position in the list (example: list[44:5]) then the return is [].  Changing the length of the range does not seem to make any difference.  Furthermore, if I use list[44], for example, then the value that is returned is correct.    I do not understand why I cannot select from a list when the cursor is not located at 0.  Can anyone tell me if lists in python have limitations on how data can be retrieved as a range?  I hope my problem and question are clear enough.  I would appreciate any feedback.  Thanks.


Turn off the built-in monitor on MBP El Capitan with clamshell open

I usually plug my MBP 15" late 2011 (El Capitan 10.11.2) with an external monitor, and I only use that. Also I need to use the trackpad.  So I need to turn off the built-in monitor with the clamshell open. Possibly using a terminal command. How can do it?  I already tried this solution (for Yosemite) but doesn't work on El capitan:   And I already tried  app but it reduces the brightness of the monitor to 0 and it remains on! So probably it consumes more. Is there a way to completely turn off?


When I'm zooming the compiled document, all brackets and similar figures look like on the screen. I've already installed cm-super, so I don't have troubles with the font, but, I have no an idea why the brackets look like this.  I have two files: the main and the style.  The preamble of the main file is:   \documentclass[10pt, a4paper]{article} \usepackage[utf8]{inputenc} \usepackage[T2A]{fontenc} \usepackage[english, russian]{babel} \usepackage{Lections_style}   In the style file kinda preamble looks:   \NeedsTeXFormat{LaTeX2e} \ProcessOptions \RequirePackage{amsfonts} \RequirePackage{amsmath} \RequirePackage{amssymb} \RequirePackage{graphicx} \RequirePackage{babel,blindtext} \RequirePackage{subfigure} \RequirePackage{hyperref} \RequirePackage{fancyhdr} \RequirePackage{cite} \RequirePackage{amsthm} \RequirePackage{xparse} \RequirePackage{mathabx} \RequirePackage{array} \RequirePackage{tabularx} \RequirePackage{multirow} \RequirePackage{makecell} \RequirePackage{mathrsfs}


Once I open the netflix-desktop the mouse pointer vanishes and doesn't appear even after I close the application. Only way I get it back is after I logoff-login.   This is the only reason I hesitate to log into Ubuntu and have to go into windows. Please help if you know solution.  I have Ubuntu 13.10.  Thanks, KK


Show that $x^p - m$ is irreducible for prime $p$ and $m \in \mathbb{Q^{\times}}\setminus \left(\mathbb{Q^{\times}}\right)^p$

I'm stuck if $m$ is not a prime or has a single prime divider (Then using Eisenstein's criterion), e.g, $m=4$ and $p=5$.  Any suggestions?


I'm not familiar with role-playing games so apologies if this question is poorly worded.   As an example of what I'm thinking of, suppose the player characters are on a ship, which capsizes. While escaping from the shipwreck they find an NPC clinging to flotsam. The players decide they cannot save the NPC, so they leave the NPC to drown. Unfortunately for them, the NPC had a quest-critical item (e.g., an artefact required to slay the BigBadBoss later). Since the item is now permanently lost, the quest will never succeed and the BigBadBoss is going to kill all the player characters. They're dead, they just don't know it yet.  How can a GM continue to progress the campaign if the player characters lose a plot-necessary item like this?  For this particular situation, I imagine the GM could attempt to give the quest-critical item to another NPC, but that might not be feasible (e.g. a player might have tried to examine the drowning NPC, and the GM described the NPC as possessing the artefact). It could also be something more severe as well, e.g. the players could kill a quest-critical NPC, and bringing the NPC back to life would be beyond belief.  I imagine the GM could also do nothing and let the players die, but then it seems like a rather dull game for the GM, since (s)he already knows the end result.  How can a GM continue to progress the campaign if the player characters cause a plot-critical item or NPC to be lost/killed?


Let $A \in M_n(F)$ be a strictly upper triangular matrix, I’m asked to construct $A$ such that $A^{n-1} \neq 0$. I know that $A^n =0$, and $A^{n-1} = A^{-1}$, and I’m confused because a triangular matrix has an inverse only if it has no zeros on its main diagonal. How can $A$ have an inverse when it is a strictly upper triangular matrix?


I met a problem with testing a method(displayEmployees), which returns a List of objects.  public class Task {     static List<Employee> employeeList;      public static void main(String[] args) {         Employee employee1 = new Employee("Dobrobaba", "Irina", "Ivanovna",                 "Moskva", 1900, 6);         Employee employee2 = new Employee("Shmal", "Anna", "Nikolaevna",                 "Krasnodar", 2017, 8);         Employee employee3 = new Employee("Kerimova", "Niseimhalum", "Magomedmirzaevna",                 "New-York", 2017, 3);         Employee employee4 = new Employee("Dobryden", "Yuri", "Viktorovich",                 "Auckland", 2014, 11);         Employee employee5 = new Employee("Lopata", "Leonid", "Nikolaevich",                 "Beijing", 2014, 11);         employeeList = new ArrayList<>(Arrays.asList(employee1, employee2, employee3, employee4, employee5));     }      /**      * Prints employees' information, which have worked more than 'n' year(s) for now.      *      * @param n years quantity      */     public static List<Object> displayEmployees(int n) {         List<Employee> requiredList = new ArrayList<>();             employeeList.forEach(employee -> {                 if (Year.now().getValue() - employee.getEmploymentYear() >= n) {                     requiredList.add(employee);                 }             });         return Collections.singletonList(requiredList);     } }   This is how I'm trying to make a test, comparing 2 Lists one with another:  public class TaskTest {     public static void main(String[] args) {         displayEmployeesTest();     }      public static void assertEquals(String testName, List<Object> expected, List<Object> actual) {         if (expected.equals(actual)) {             System.out.println(testName + " passed");         } else {             System.out.println(testName + " failed: expected " + expected + ", actual " + actual);         }     }      private static void displayEmployeesTest() {         List<Object> expectedList;         Employee employee1 = new Employee("Dobrobaba", "Irina", "Ivanovna",                 "Moskva", 1900, 6);         Employee employee2 = new Employee("Shmal", "Anna", "Nikolaevna",                 "Krasnodar", 2017, 8);         Employee employee3 = new Employee("Kerimova", "Niseimhalum", "Magomedmirzaevna",                 "New-York", 2017, 3);         Employee employee4 = new Employee("Dobryden", "Yuri", "Viktorovich",                 "Auckland", 2014, 11);         Employee employee5 = new Employee("Lopata", "Leonid", "Nikolaevich",                 "Beijing", 2014, 11);         expectedList = new ArrayList<>(Arrays.asList(employee1, employee4, employee5));          assertEquals("displayEmployeesTest", expectedList, displayEmployees(3));     } }   Problem is - I get an error "java.lang.NullPointerException", running TaskTest.  What is the reason of that error occurrence? Thank you for your attention!


Linux: set up media server to stream video via the Internet?

How do I set up a media server in Linux which streams video over the internet?  Is it easy to do this? I want a server that will actually encode video in real time to allow it to stream over sometimes slow or unreliable networks. Basically, I want a server that works on the internet.  I have a directory with a bunch of video files, and want to make this accessible to myself remotely.  For other situations, I found great and useful software (such as the PS3 media server). I'd like to find something equally as useful for streaming video over the internet.


Is there a way to make a custom hotkey for specific functions? Like to solve my problem here: I’m working on a piece, its a replica and I have many references setup in some collections and I need to hide/unhide the collections all the time. I do it by hitting the relevant checkbox in the object browser list. Can I somehow hotkey that specific checkbox? If coding, IK how to code, but I do not know how to get console or script in blender, or at-least I need a ‘pointer’ to get started.


how to get definition of a function in python?

I have a function mentioned below in python:  >>> students=[]  >>> def add_student(name): ...     students.append(name)   How can i get actual text of add_student?


What CSS properties can be applied to which HTML elements

I'm looking for a source/spec that can tell me what CSS properties can applied to which HTML elements.  For instance, the css property; "overflow".  I know I can apply this to div, p, textarea but what other elements can I apply this too?  Is there a spec somewhere I can reference?


I am using Dell Inspiron with Broadcom wireless adapter. I cannot see my wireless connection. I recently reinstalled ubuntu 18.04. I can see other Wifi connections but not mine.


How to replace the background image in the default plymouth theme

Is it possible to replace the pink purple colour of Ubuntu's default plymouth theme with an image?


How to use the free space after narrow /home partition in Ubuntu 14.04

I want to install windows7 with my current system ubuntu,and the first step I should do is to allocate a partition for win7.So I decided to narrow my /home patition.Therefore,I execute the following command line  umount /home e2fsck -f /dev/sda3 resize2fs -p /dev/sda3 150G mount /dev/sda3 /home   It worked. And then I viewed the information by df -lh  Filesystem      Size  Used Avail Use% Mounted on udev            1.9G  8.0K  1.9G   1% /dev tmpfs           384M  1.3M  383M   1% /run /dev/sda1        23G   12G   11G  53% / none            4.0K     0  4.0K   0% /sys/fs/cgroup none            5.0M     0  5.0M   0% /run/lock none            1.9G  164K  1.9G   1% /run/shm none            100M   52K  100M   1% /run/user /dev/sda3       148G   87G   54G  62% /home   But I don't know how to do next.How can I make use of the free space?


How do I make a Java JAR file executable in Linux Mint?

This is the notice I get:   The file '/home/heart/Phantombot/PhantomBot-2.4.1/PhantomBot.jar'  is not marked as executable.  If this was downloaded or copied from an untrusted source, it may be dangerous to run.  For more details, read about the executable bit.   Basically, the JAR file doesn't have the necessary permission to run. How do I give it this permission?


What's the correct way to configure wireless connections in Ubuntu Server 15.10 with systemd?

With reference to this question (), is there a canon way of configuring a wireless connection using systemd, because there doesn't seem to be any up-to-date documentation on the Ubuntu wiki or elsewhere.  I have an Intel wireless 3945ABG and I'm trying to configure it but there is no clear advice on the correct way to do this with systemd. So should I use systemd or the 'old way'?


Do I need to read Ian Cameron Esslemont's novels?

I am currently up to book 6 in the Malazan Book of the Fallen.   Having solely read Steven Erikson's line, am I missing out on vital information.   I know that the two lines are somewhat separate but cannot find if I need to read both to fully appreciate the story.  For example are there gaps in the Erikson series that are explained by the works of Esslemont?


vertically align link next to image with CSS

EDIT: Yes, this is a duplicate, my mistake (I am new to CSS).  But can anybody explain the rationale behind aligning the image, as opposed to the link / text?  Is there some larger concept at work here that would help me understand the concepts of CSS better and avoid problems like this in the future?  Original (Duplicate) Part: I have a scenario where I want to have a link next to an image on my page, and the link should be aligned so that it is vertically centered with the image.  Of course I don't know the exact height of the image, so this should be done dynamically.  Given this chunk of HTML, how would I achieve such a thing with CSS?
          My Link!
   I have a , and you will note that I have placed some size information in the image class.  This is just to simulate an image of unknown size, so please consider the question without it.


Empathy won't connect to my Facebook account

When I try to connect Empathy to my Facebook account, the following error appears:    Rough translation: "Error connecting to the app. Sorry, but the app you are trying to access doesn't exist or was deactivated."  What can I do to solve it?


After my suspension period, my reputation was not returned

On Stack Overflow, I have a suspension period of 7 days which ends today. But my actual reputation has not been returned to me as one of the moderators said it would. I have a message like this by @Andrew Barber:     Once your suspension period is over, you will be returned to your   correct reputation level, minus the votes from the accounts which have   been deleted. At that time, you are more than welcome to return, and   continue contributing your knowledge, and gaining legitimate   reputation points. Just please keep our rules in mind when you do.      Regards      Andrew Barber, Stack Overflow moderator   Can any moderator here help me or tell me what the rules are of getting back my reputation?  How can I get the attention of a moderator so that they can resolve my problem?


Can any one explain me to how to configure VPN server in Ubuntu 14..? am about to deploy a VPN server for my firm next week please help me.. Thank you in advance.


See render preview in a second monitor while modelling

I have two monitors and I want the preview render to be on one screen and modelling it on the other. I can't do this because I can split the render and preview but they are in the same window.


What is the intuition behind the finite sample adjustments in the Ljung-Box test: $Q = n\left(n+2\right)\sum_{k=1}^h\frac{\hat{\rho}^2_k}{n-k}$?  Degrees of freedom adjustments usually involve subtraction, so where does the $(n+2)$ come from?   Also, why are farther lags weighted more in the $(n-k)^{-1}$ adjustment?


Can I prevent the screen from scrolling when dragging a vector path in Illustrator?

Sometimes, when I'm drawing a vector path with the pen tool, I need to drag the line further than I have screen space, and this makes the screen scroll down, which makes me lose focus on what I'm looking at.   Is there a keyboard shortcut or some way to prevent the screen from automatically scrolling downward (or whatever direction) and just allow me to drag it as far as I want?


Prove that there is no increasing function $f: \aleph_1 \to \mathbb{R}$

Someone gave a hint for this problem. Hint: if such a function existed, there would be a rational between $f(\xi)$ and $f(\xi + 1)$ for each $\xi < \aleph_1$. But I don't know how to apply this hint to the problem. Maybe I think I should use the fact that the set of rational numbers is countable, but how?


Let $R$ be a commutative ring, $P \in M_n(R)$ and $\det(P)$ is a zero divisor of $R$. Must $P$ be a zero divisor of $M_n(R)$?   Here rings mean unital rings, $M_n(R)$ denotes the ring of square matrices over $R$ of order $n$, and zero divisor is understood to be nonzero. The difficulty lies in that the adjugate matrix of $P$ may well be $0$.


How to change PostGIS feature attributes via openlayers 3+?

I am trying to find a working example of editing the attributes of a feature in a PostGIS table published in GeoServer (2.8), using Javascript libraries like openlayers (3 & 4).  The closest thing I can find is  from the openlayers documentation, but it only touches geometry not attributes. In addition it is based on GeoJSON, not a database backend.  The next closest is an , but it's just a blog with a screenshot without and code snippet. Also relevant is a similar GIS.SE question: . The answer there suggests that one has to program it from javascript.   Before reinventing some wheels, can anyone give me some pointers how to implement such a function for setting the attribute of a feature?  FYI, I have copied the said openlayers 4 example below as a starting point.  <!DOCTYPE html>         <title>Modify Features</title>     <link rel="stylesheet" href="https://openlayers.org/en/v4.0.1/css/ol.css" type="text/css">

            -- EDIT --  This is not a duplicate of the said question , as that question is about OpenLayers 2. As said in the beginning, my question is about OpenLayers 3&4, which is not backwards compatible with Openlayers 2, and missing a large number of features in OpenLayers2. So the said question/answers don't apply here. I've also used the openlayers tag per tag description to differentiate this from openlayers2 questions.


I submitted a question on Stack Overflow and when I went back to check answers I saw two. I immediately saw two answers, but the first one which happens to be more detailed and a better explanation (to some degree).   I checked that one as the correct solution. I saw the other person's solution, and it is also correct. He commented to me that he was first.  I want to clarify in a thread where there are multiple right answers. Should whomever's first get the correct solution or whomever is better explained when the next person comes?  Question:


I know it's weird, but I am just curious.  Tomorrow is Christmas Eve.  And today is the eve of tomorrow. Is it proper grammar to say that today (December 23) is Christmas Eve Eve?


Which role playing games are suitable for a family with children under 10?

First post; please be gentle.  I grew up in an environment with no exposure to role playing games (only child, frequent relocation, no base of friends).    Now I have three children of my own.  I want to give them a broad experience of games and game playing beyond the computer or board game variety.  They are 4, 6 and 8; all three are creative and imaginative.     Which role playing games are suitable for families, or should I wait a few more years?


Attempt to invoke virtual method Notification Mananger

NotificationManagerCompat mNotificationManager; /..onCreate mNotificationManager = NotificationManagerCompat.from(getApplicationContext());  /.. code @RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN) public void CreateNotification(String code){     NotificationCompat.Builder notifiationBuilder = new NotificationCompat.Builder(context);     notifiationBuilder.setSmallIcon(android.R.drawable.ic_menu_send)             .setContentTitle("My notification")             .setContentText(code);      mNotificationManager.notify(0, notifiationBuilder.build()); }     Error:  Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.pm.ApplicationInfo android.content.Context.getApplicationInfo()' on a null object reference     at android.app.Notification$Builder.<init>(Notification.java:2386)     at android.app.Notification$Builder.<init>(Notification.java:2375)     at android.support.v4.app.NotificationCompatApi24$Builder.<init>(NotificationCompatApi24.java:64)     at android.support.v4.app.NotificationCompat$NotificationCompatApi24Impl.build(NotificationCompat.java:918)     at android.support.v4.app.NotificationCompat$Builder.build(NotificationCompat.java:1844)


Cardinality of equivalence relations in $\mathbb{N}$

I came across this long proof on this site:    But I would like to know whether my direction can work.  Say we want to find the cardinality of all equivalence relations in $\mathbb{N}$. Since it is a subset of all relations in $\mathbb{N}$, I conclude it has a cardinality smaller or equal to $\aleph$. Now, define an injective function from $P(\mathbb{N})$ to the set of equivalence relations by matching each subset of $\mathbb{N}$ with the identity relation (which is an equivalence relation in $\mathbb{N}$.  Therefore the cardinality of all equivalence relations in $\mathbb{N}$ is greater or equal to $\aleph$ and using CSB we get the desired result.  Seems legit?


Word for a mind apt to seeing double entendres

The other day, I was hunting for a word to describe someone I know. The trait denoted by this word is the tendency to rapidly spot--as though unconsciously seeking out--double meanings, especially of the racier sort, in messages whose intent was probably innocuous.


Awkward javascript behavior mapping arrays?

Fails both on chrome and node 8.x  ["4", "5"].map(x => parseInt(x)) // [4, 5] ["4", "5"].map(parseInt) // [4, NaN]   WHAT?


I currently hold Schengen visa type C multiple entries valid for one year (from 10 December 2014 - 09 December 2015). So far I have two entries: 18 December 2014 - 11 January 2015 (25 days) and 25 March 2015 - 21 April 2015 (28 days). The total stay is now 53 days. I believe the half year (180 days) for my visa is at 15 June 2015. Now, I planned to stay in Germany from the 26th of May - 6th of September. That would make 104 days. However, it is an overlap between two half year as my first half year ends on the 15th of June. My question is, is it possible to combine the stays from two half year allowance together? Or is it that I must stay in EU zone for only 90 days with or without the overlap?


How can I easily switch audio output in Ubuntu 17.10 and later with GNOME?

I am using external USB audio card to handle speakers, also got the headphones connected to jack port. I need to switch them few times a day and getting extremely frustrated, as the only way I've found is:   Open search tool. Type: se. Click on 'Settings'. Navigate to 'Sound'. Change output to desired one.   On Unity I could navigate to 'Sounds Settings' from the audio icon in the tray. No idea how to do that on GNOME. Other than this finding GNOME superior to Unity. Happy that Canonical made that move.


How to check how long a process has been running?

I would like to avoid doing this by launching the process from a monitoring app.


Find the volume inside the paraboloid $x^2+4z^2+8y=16$ and on the positive side of xz-plane

No answer was given for this question, so wanted to confirm my answer. Steps followed for solving:  V=$4\int_0^2\int_0^{\sqrt{16-4z^2}}(2-\frac{x^2}{8}-\frac{z^2}{2})dxdz$  After solving this I got V = $8\pi$. Is this answer correct?


Texture loading: Everything at once OR un-/loading the needed assets?

Good evening. We've been developing quite a huge game for android on the basis of AndEngine. So we have a lot of assets to load, especially textures.  At the moment everything (sound, textures etc) for every screen (menu, shop, etc etc) is loaded when the app starts (while showing a progress bar). This way the user only has to wait once about 16 seconds at the start of the game. We think that this is a pretty pleasant solution from the users perspective but might it be bad in terms of battery usage / memory usage or any other reasons?  What arguments speak for a solution where we unload all the screen specific assets of the active screen and load the assets needed for the next screen? Thank you for your opinion!


On Windows it is possible to enable revealing the mouse pointer position by pressing the CTRL key.  Is this possible in Gnome? There doesn't seem to be a setting, unless it's hidden somewhere.


How this statement works `int k = (a++, ++a);` in c or c++

I am unable to understand how the output of the below code is "-3" ?  #include <stdio.h> void main() {     int a = -5;     int k = (a++, ++a);     printf("%d\n", k); }   What is the concept behind this  int k = (a++, ++a); statement in c or c++?


Example of quasi-compact, non-quasi seperated scheme where qcqs fails?

The qcqs lemma (in Ravi Vakil's notes) says that if $X$ is a quasi-compact (qc) and quasi-separated (qs) scheme, for any global section $f$, the natural map from $\Gamma(X, O_X)_f \to \Gamma(X_f, O_X)$ is an isomorphism.  (We are defining $X_f$ to be the complement of the set where $f(p) = 0$, i.e. where $f = 0$ in $O_{X,x} / m_x$. So the natural map is the one guaranteed by the universal property of localization as $f$ becomes a unit over $X_f$.)  The proof of this lemma uses in a crucial way these finiteness assumptions in order to take advantage of the willingness of localization to commute with finite products. (One builds the exact sequence describing the global sections via the sheaf axioms, plugs a finite affine cover with a finite affine cover of the overlaps into it. Then localizing this sequence expresses $\Gamma(X, O_X)_s$ as the kernel of the exact sequence describing $\Gamma(X_s, O_X)$, bootstrapping off of the case of this theorem in the affine case.)  I want counter examples in the situation when this hypothesis has been dropped.  Here is what I have been thinking so far:  I tried the example of the only qc but not qs scheme that I know: the infinite affine space with a doubled origin. The functions on this space and on any open subscheme are the same as functions on the corresponding open $\mathbb{A}^{\infty}$, since the gluing identifies the variables on a dense open set. So I don't think this will provide an example (but I am not sure - now after thinking about this I am more convinced that this example would provide a counter example, but I don't see how). Here one would (obviously) need to use that infinitely many affines are required to cover the intersection of the two $\mathbb{A}^n$ in order to produce something...   I think I found an example of a quasi-seperated non-quasi compact scheme that provides a counter example. Essentially the point is that localization doesn't commute with infinite products in general, so one can take the infinite disjoint union of $Spec Z / (2^i)$, for all $i \geq 0$, and try to invert the element $2$. $X_2 = \emptyset$, but $(\Pi Z / 2^i)[2^{-1}] \not = 0$, since for instance $(1,1,1,1, \ldots)$ is not 2-torsion.


How can I install Ubuntu in a computer without an OS?

I got a computer from my office and ordered IT to wipe it all from Windows OS. Now how can I get Ubuntu OS on this computer?


Why is an object pushed when you push it?

According to Newton's third law, if I push an object the object should push me back with the same and opposite force. So there should be no net force, which means that it shouldn't be displaced (pushed).  But in reality it's not!!! How do I understand this?