Prove if a non-trivial ring $R$ has a unique maximal left ideal $J$ , then $J$ is two-sided and is also the unique maximal right ideal in $R$.

If a non-trivial ring $R$ has a unique maximal left ideal $J$ , then $J$ is two-sided and is also the unique maximal right ideal in $R$.  I can prove that it is two sided, but I can't prove that it is unique.  My proof:  Let $r \in R$. Then $Jr$ is a left ideal. If $Jr = R$, then $jr = 1$ for some $j \in J$. Note that $rj \in J$ since J is a left ideal, so $rj \neq 1$. Using a lemma, $1 - rj$ is not left invertible, which is to say that $R(1-rj) \neq R$. But then R(1-rj) is contained in a maximal left ideal, i.e. $1-rj \in R(1-rj) \subseteq J$, so $1= rj +(1-rj) \in J$, which gives a contradiction. Hence $Jr \neq R$. This implies that $Jr$ is contained in $J$. Since the choice of $r$ is arbitrary, $jr \in J$ for all $j \in J$ and $r \in R$. Hence, $J$ is a two sided ideal.  Can someone tell me how I can prove uniqueness?


In the twins paradox, the twin that travels away from earth comes back to find that his (her) twin has aged much more due to relativity's effect on time. Why can't we posit that it is not the one twin moving away from Earth at the speed of light, but it is the entire universe, the earth and his twin included, who are accelerating and moving away at the speed of light and then coming back? In this case shouldn't be the other twin to have aged less? (and, in fact, the whole universe) What is wrong with this way of thinking?  This has NOTHING to do with the other question. I am asking what is wrong in my thought-experiment in which the whole universe accelerates away at the speed of light and then comes back. There clearly is an asymmetry here I am missing, and asking what it is. The other question is asking to clarify the twins paradox, it is not addressing the asymmetry.


How do I bake/add material colors onto my UVmap?

I looked everywhere from tutorials to documents and either they only talk about texturing or they are doing the tutorial in 'blender render' when I need it in 'cycles render'.   I have a cube that is toon shaded red. And as you can see it is unwrapped to show the map.    Now I would like to add the color that's on the cube onto the map.   As you can see at the bottom of the image that I created a new image called 'untitled'. Now the next step of baking the colors onto the map is where I become lost. Regardless of which 'Bake Type' that I used, I keep getting error messages like: No valid selected objects.  Everything looks selected to me. No, I am not new to Blender but I am new to color baking. Thank you for any help provided; I used a simple cube first before using other models I already created.


Prove by induction $ \sin x + \sin 2x + ... + \sin nx = \frac {\sin (\frac {n + 1} {2} x)} {\sin \frac{x}{2}} \sin \frac{nx}{2} $

Prove by induction    $$ \sin x + \sin 2x + ... + \sin nx = \frac {\sin (\frac {n + 1} {2} x)} {\sin \frac{x}{2}} \sin \frac{nx}{2} $$   What I have for now: $$  \frac {\sin (\frac {n + 1} {2} x)} {\sin \frac{x}{2}} \sin \frac{nx}{2} + \sin(n + 1)x =  \frac {\sin (\frac {n + 2} {2} x)} {\sin \frac{x}{2}} \sin \frac{(n + 1)x}{2}$$ Letting $y = \frac {(n + 1)x} {2} $   $$\frac {\sin y} {\sin \frac{x}{2}} \sin (y - \frac{x}{2}) + \sin2y =  \frac {\sin (y + \frac {x} {2} )} {\sin \frac{x}{2}} \sin y $$  Then I used $\sin (\alpha + \beta)$ and $\sin (\alpha - \beta)$ formulas, bit they didn't help.


Why is $(\mathbb{Q}, \cdot )$ not a group?

So I have given the following question; Is ($\mathbb{Q}, \cdot)$ a group? A group is defined by the monoid $(\mathbb{Q}, \cdot)$ and the inverse for $\cdot$. Since these (afaik) hold:  Associativity is true: Take $a, b, c \in \mathbb{Q}$: $a(bc) = (ab)c$ There is a neutral identity: $1$ $\forall a \in \mathbb{Q}: \exists a^{-1}: a \cdot a^{-1} = 1$  Why isn't $(\mathbb{Q}, \cdot)$ a group?


I wrote this code  List<Object> result = null;  .... Object resultObject =method.invoke(o, "test", "test"); System.out.println(resultObject); result.add(resultObject);   resultObject contain the result that I expect but the last line caus a NullpointerException.


I think it might be a good idea to have a URL-shortening service for each of the Stack Overflow family of sites.  Since questions, and answers all have a unique id, it should be fairly easy to use that for shortening the URLs.    For example: (Could easily be shorter)   http://short-SO-url.com/1234   This could easily point to a question, or an answer. All this would need to do is redirect to:   http://stackoverflow.com/questions/1234   Or if it is an answer, point to:   http://stackoverflow.com/questions/{question-id}/-/1234#1234   You need something between the question id, and the answer id. That is why there is /-/ in the URL.    Right now, if you want a shorter URL, you have to use a third-party URL shortener which can point to anywhere. It is also difficult, or impossible to know that it doesn't redirect to a malicious website. If there were an official URL shortener that only worked for Stack Overflow, you would know for sure that it is safe.    This would be easier if there was an internal interface to redirect to the correct URL.   http://stackoverflow.com/api/post/1234.301   It could redirect to the correct URL regardless of if it is an answer or a question. 301 redirect


How to transfer the following matrix into Smith normal form? $$\left[\begin{matrix} 2   & -2b & 0   \\ 0   &  2  & -2c \\ -2a &  0  & 2 \end{matrix}\right]$$ The final answer is $$\left[\begin{matrix} 2 & 0 & 0 \\ 0 & 2 & 0 \\ 0 & 0 & 2|abc-1| \end{matrix}\right]$$  But how we get it?


Deploying QGIS settings in an enterprise environment

Are there any recommendations to manage and deploy various settings in QGIS (GUI-settings like visible plugins/toolboxes etc., settings in options, print compositions ...) to hundreds of clients / users?  Automated software installation is done so far (), but this comes with a standard configuration of the gui, which has by far too many options for a normal user, who only wants to see and print spatial data.


What is the difference between && and ||?

I'm getting it difficult to understand how the following programs work, kindly help me in understanding.  int x=2,y=0;   (i)     if(x++ && y++) cout<<x<<y;   Output:  (ii)  if(y++ || x++) cout<<x<<" "<<y;   Output: 3 1  (iii)  if(x++||y++) cout<<x<<" "<<y;   Output: 3 0  Kindly explain me how the program is working and also, what makes the difference between (ii) and (iii).


Image with transparent bg over opaque image

I want to overlay a line image (no background, just the lines) on top of a solid image so that the lines are superimposed over the other, opaque image. I've tried it with the overlay as both a PNG and a GIF, but it keeps displaying as solid, completely covering up the second image. I've even tried playing with the z-index to no avail. Is this not possible? If it is, do you know what I'm doing wrong?         .Overlay {         position: relative;         display: block;         }             .Solid {         position: absolute;         top: 0;         left: 0;         }


Does SQLDeveloper support executing scripts?

I was trying to follow some instructions today, and it starts with the comment    REM  In SQLPlus I manually copy in each line and execute it.   That's nice, I don't have SQLPlus, I have SQLDeveloper.  The lines that were pasted in were of the type:   @\\server\dir\dir\dir\commandfile1.txt; COMMIT;   ...etc.  It didn't like it when I tried that in a SQL window.  I opened up and pasted in the commands by hand, and it wasn't happy with that either.  (Did I mention that I'm not so good with this application nor Oracle, but that everyone else was out today?)  The files there started with code like:   rem set echo on rem execute procedure_name ('parameter1', 'parameter2');   A co-worker did have SQLPlus, and together we got it resolved.  But, is there a way for me to do this with SQLDeveloper, so I'm not stuck if he's out too?


We already have the spoiler formatting      like this   for information that should be hidden until specifically needed (by hovering), and the code snippet formatting    like this     for code that can be revealed and left visible, but when answering questions that ask specifically for a hint, or a direction (e.g. my answer ) it would be very useful to be able to either create a hierarchical spoiler (such that viewing spoiler 3 reveals spoilers 1 and 2 as well), or a non-code snippet (such that the user can expand the entire post without having to use 'Ctrl+A' to view everything inverted), in order to provide the information that the question asks for specifically, while still solving the problem for future visitors who may want more than a hint.  The collapsing is covered in part by , but the idea of hierarchical / sequential spoilers has not been raised / addressed before.


Prove that $\int^1_0 f(x)\,dx = f(0)+\frac12f^\prime(c)$

Let $f$ be a differentiable function $f\colon [0,1] \to \mathbb R$, and assume $f^\prime$ is continuous. Prove that there exists $c\in(0,1)$ such that $\int^1_0 f(x)\,dx = f(0)+\frac12f^\prime(c)$.  I tried to apply the Mean Value Theorem from which I got \begin{align*} f^\prime(c)& =f(1)-f(0), \\ f(c) & =\int^1_0 f(x)\,dx, \end{align*} both of them for some $c\in(0,1)$.


Uses undefined class - Forward Declaration C++

I have the following program in which I have 2 classes, namely Class A and Class B in which each class has instance of another class declared as a private member.  FYI, for one class I'm using dynamic allocation (pointer instance) and in the other class I'm using automatic allocation (normal instance).  (Program.h)   class A; class B;  class A {     A();     ~A();     public:     void InitA();     void funcA;     private:     B b; // ERROR! on code compilation: "A::b uses undefined class B" }  class B {     B();     ~B();     public:     void InitB();     void funcB;     private:     A *a; } </code>   (Program.cpp)   B::B() : a(new A())     {     }     B::~B()      {          SAFE_DELETE (a);      }     B::InitB()     {         a->funcA(); // works beautifully!     }       A::A()      {     }     A::~A()      {       }     A::InitA()     {         b.funcB(); // DUE TO ERROR, code never compiles so I don't see this.     }   ERROR: "A::b uses undefined class B"  Now, I've deliberately not declared a pointer instance of class B in class A, which I believe should not be the reason for this error. This error is probably because I'm not doing forward declaration properly.


I met a sugar daddy online who claims he cannot use cashapp or paypal to compensate me and can only use bitcoins. I made a coinbase account and now he is asking for my coinbase login so he can "load my account with his cryptography watcher and it will be loaded"  I am just skeptical because i have read about cases of people getting scammed with money laundering in regards to bitcoins since it leaves a digital trail of where the bitcoins gets transferred.   Could he be attempting to scam me? What could he do with my bitcoin account if he were to have access to my login?


TestClass for throwing Exception while testing Trigger

I writing my first Testclass to test my first Trigger and encountered some error.  I have written a trigger to update the Phone number of all contacts when its Accounts Phone number is updated. Its working fine when I change the phone number of Account via UI, its updating the related Contacts Phone number using trigger.   But when I try to test it via Testclass by updating the Phone number of Account via code, its showing some error while running.   Error: System.QueryException: List has no rows for assignment to SObject Stack Trace: Class.UpdateAccountPhoneUnitTest.AccountPhoneUpate: line 5, column 1    Can someone please help me to understand what went wrong inside my TestClass and how it can be fixed?


What is the form of energy that is forming while lifting a suitcase

If I am lifting a heavy suitcase and I am not moving at all. Abviously I am not doing work because I am not moving or rising the suitcase up and down. But abviously I am losing chemical  energy since I am getting tired, so what form the chemical has transformed to. Is it heat or what. Thank you.


I want to know if it's possible to write out the line \def\TEMP{ to a file, and then later write } to close the brace-pair in the written file? Essentially I'd like to do;  \documentclass{article} \newwrite\TEMP \immediate\openout\TEMP=Temp.tex \begin{document} \immediate\write\TEMP{    \def\writefoo{% I don't want to close this brace at this point     }% This is suppose to close the \write command, not the \writefoo{ brace \newcommand{\foo}{This is some text} \immediate\write\TEMP{\foo} \immediate\write\TEMP{    }% This is the closing brace to the original write-out.    } \end{document}   I know the problem with the above code is that the \def\writefood{ closes on the } that I want to be the closing brace on the \write command, thus the \write command doesn't actually get closed.  My question is, is there a way to trick latex into writing out the unbalanced brace to the file? Since it's being written out to a file it seems like this would be plausible (if you can convince latex to close the brace artificially everything else would compile fine).  I tried to use \begingroup and \endgroup but that, predictably, did not work correctly as the resulting \def\writefoo's contents don't persist correctly.  Edited to answer questions below thoroughly:  I currently have a complex series of macros that output randomized large blocks of text, containing complex macros as well. I have managed to write them out as they are selected/generated in sequence thanks to the unexpanded command, you can see more about the specifics .   However, (as it says at the bottom of that link) I want to be able to output more than one selection set. The best way that comes to mind is to define dynamically named macros that are just shells containing all the contents from a single large selection call. That way I can input the file and call the macros I want to use, and just not call the ones I want to regenerate.  The problem is, since the content is generated sequentially and randomly, the only way I can think to do this is to put a \def at the start, then generate and export all the content, then close the def. But that means writing out to the file unbalanced braces which LaTeX doesn't like.


Ubuntu 16.04 apache tls settings wont affect

My setup is fresh Ubuntu 16.04 server installation with Apache 2.4.18 and Openssl 1.0.2g. I have made ssl configs to /etc/apache2/mods-available/ssl.conf and checked that there are no same configs in vhost -files etc. Still no matter what I do I cant get no change on ssllabs.com raport. I tried even comment all SSLProtocol and SSLciphersuite lines but still no change. Yes I have restarted the server after the changes.   What am I missing?


If G is a p-group, the number of nonnormal subgroup is a multiple of p?

I want to show that     If $G$ is a finite $p$-group, then the number of nonnormal subgroups of $G$ is a multiple of $p$.   I think I need to consider a conjugation action. But then?


Why does my Minecraft 1.10 keep crashing right after I hit play?

[20:55:44] [Client thread/INFO]: Setting user: MCAnimate.KDZ [20:55:46] [Client thread/INFO]: LWJGL Version: 2.9.4 [20:55:46] [Client thread/ERROR]: Couldn't set pixel format org.lwjgl.LWJGLException: Pixel format not accelerated     at org.lwjgl.opengl.WindowsPeerInfo.nChoosePixelFormat(Native Method) ~[lwjgl-2.9.4-nightly-20150209.jar:?]     at org.lwjgl.opengl.WindowsPeerInfo.choosePixelFormat(WindowsPeerInfo.java:52) ~[lwjgl-2.9.4-nightly-20150209.jar:?]     at org.lwjgl.opengl.WindowsDisplay.createWindow(WindowsDisplay.java:247) ~[lwjgl-2.9.4-nightly-20150209.jar:?]     at org.lwjgl.opengl.Display.createWindow(Display.java:306) ~[lwjgl-2.9.4-nightly-20150209.jar:?]     at org.lwjgl.opengl.Display.create(Display.java:848) ~[lwjgl-2.9.4-nightly-20150209.jar:?]     at org.lwjgl.opengl.Display.create(Display.java:757) ~[lwjgl-2.9.4-nightly-20150209.jar:?]     at bcx.ap(SourceFile:585) [1.10.jar:?]     at bcx.an(SourceFile:434) [1.10.jar:?]     at bcx.a(SourceFile:381) [1.10.jar:?]     at net.minecraft.client.main.Main.main(SourceFile:124) [1.10.jar:?] ---- Minecraft Crash Report ---- // Why is it breaking :(  Time: 6/17/16 8:55 PM Description: Initializing game  org.lwjgl.LWJGLException: Pixel format not accelerated     at org.lwjgl.opengl.WindowsPeerInfo.nChoosePixelFormat(Native Method)     at org.lwjgl.opengl.WindowsPeerInfo.choosePixelFormat(WindowsPeerInfo.java:52)     at org.lwjgl.opengl.WindowsDisplay.createWindow(WindowsDisplay.java:247)     at org.lwjgl.opengl.Display.createWindow(Display.java:306)     at org.lwjgl.opengl.Display.create(Display.java:848)     at org.lwjgl.opengl.Display.create(Display.java:757)     at org.lwjgl.opengl.Display.create(Display.java:739)     at bcx.ap(SourceFile:598)     at bcx.an(SourceFile:434)     at bcx.a(SourceFile:381)     at net.minecraft.client.main.Main.main(SourceFile:124)   A detailed walkthrough of the error, its code path and all known details is as follows: ---------------------------------------------------------------------------------------  -- Head -- Thread: Client thread Stacktrace:     at org.lwjgl.opengl.WindowsPeerInfo.nChoosePixelFormat(Native Method)     at org.lwjgl.opengl.WindowsPeerInfo.choosePixelFormat(WindowsPeerInfo.java:52)     at org.lwjgl.opengl.WindowsDisplay.createWindow(WindowsDisplay.java:247)     at org.lwjgl.opengl.Display.createWindow(Display.java:306)     at org.lwjgl.opengl.Display.create(Display.java:848)     at org.lwjgl.opengl.Display.create(Display.java:757)     at org.lwjgl.opengl.Display.create(Display.java:739)     at bcx.ap(SourceFile:598)     at bcx.an(SourceFile:434)  -- Initialization -- Details: Stacktrace:     at bcx.a(SourceFile:381)     at net.minecraft.client.main.Main.main(SourceFile:124)  -- System Details -- Details:     Minecraft Version: 1.10     Operating System: Windows 10 (x86) version 10.0     Java Version: 1.8.0_91, Oracle Corporation     Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation     Memory: 79884784 bytes (76 MB) / 149696512 bytes (142 MB) up to 523501568 bytes (499 MB)     JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M     IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0     Launched Version: 1.10     LWJGL: 2.9.4     OpenGL: ~~ERROR~~ RuntimeException: No OpenGL context found in the current thread.     GL Caps:      Using VBOs: Yes     Is Modded: Probably not. Jar signature remains and client brand is untouched.     Type: Client (map_client.txt)     Resource Packs:      Current Language: ~~ERROR~~ NullPointerException: null     Profiler Position: N/A (disabled)     CPU: <unknown> #@!@# Game crashed! Crash report saved to: #@!@# C:\Users\Family\AppData\Roaming\.minecraft\crash-reports\crash-2016-06-17_20.55.47-client.txt Java HotSpot(TM) Client VM warning: Using incremental CMS is deprecated and will likely be removed in a future release


Product of two positive compact, self adjoint operators

If we have two positive compact , self adjoint operators; $A$, $B$. Is the product $AB$ a positive operator?


If gravitons (or some other quantum particle) are indeed responsible for the effect of gravity, can gravity be blocked, defected or trapped somehow?  Is there any evidence that a gravitational field can be augmented at all, other than by another massive object?


Exception handler on multiple row insert PostgreSQL

I'm trying to create a function which inserts rows from one database table to another, this is the part of the function which goes wrong:  BEGIN   INSERT INTO suppliers("id","name", "url", "logo", "clicks", "order")                 SELECT * FROM dblink('dbname=linkeddatabase', 'SELECT id,"name", url, logo, clicks, "order" FROM suppliers')                 AS supp(id int,"name" character varying, "url" character varying, "logo" character varying, "clicks" int, "order" int);   EXCEPTION WHEN unique_violation THEN   -- do nothing END;   Problem:  It looks like it stops as soon as it reaches a duplicated row. Cause as soon as the function is finished, my table contains the same amount of rows...  What I want: If it needs to insert 1000 rows, of which the first 100 are duplicated, it still needs to insert the last 900 rows. Any ideas to fix this with the current function?  Or do I just need to create some loop?


Is there a way to properly pluralize a quotation, if I must and can't just rearrange the sentence to avoid it (or do not wish to rearrange it for artistic purposes)? Example:  We exchanged many "I love you"s/ 'I love you's/ "I love you" 's.  Or would this simply be left unquoted?


What does 1x1 convolution mean in a neural network?

I am currently doing the Udacity Deep Learning Tutorial. In Lesson 3, they talk about a 1x1 convolution. This 1x1 convolution is used in Google Inception Module. I'm having trouble understanding what is a 1x1 convolution.  I have also seen  by Yann Lecun.  Could someone kindly explain this to me?


Shading artifacts in Cycles with no apparent cause

Why is my shading producing artifacts? I've search around with no solution. I can get a smooth look in Solid view, but Cycles and Eevee create artifacts. the topography is clean, no ngons, subdivided. Things I've tried: -Recalculating normals -checking for n-gons (there are none)  Merge by distance to check for overlapping vertices (none) smoothing options in Mesh->Shading.  The only thing that has worked is subsurf modifier, but I don't want to use that. The model was imported as an .obj, and I find that most imported .objs have similar problems. What can I do to get a smoother look, like in solid view? Thanks


failed to install grub, ubuntu 17.04 installation

Linux newbie here I've tried to install Ubuntu 17.04 but it crashed and show this message dialog " the 'grub-efi-amd64-signed' package failed to install into /target/. Without the GRUB boot loader, the installed system will not boot. "   This is my boot-info link   Then i try to repair it using boot-repair and follow the instruction until it finish(im not sure i've done it correctly). next, i can boot ubuntu but crash report show up "sorry, a problem occured while installing software. Package :grub-efi-amd64-signed 1.80.2+2.02~beta3-4ubuntu2.2"  Is there any correlation with forcing uefi installation?  Thanks for your help


How can i do cumulative sum?  My query is :  select dateb,ricetype,bajet1 from bajet where ricetype='grand total'   How do i archieve 'New Value'?


Relevance of Mixed Model Estimates vs. Observed Means

This question is a follow-up to a previous question I asked regarding mixed model effects construction, . It provides some background, although this is a broader question with little to do with specifically my model. I have since constructed my model, taking care that assumptions are met etc. But at the risk of asking a perhaps noobish question, I'm struggling to get my head around the output and how to go about reporting it. Via the model I can generate what I have taken as estimates for the mean of each of my 10 treatment conditions for each of the three time steps, done via simple addition method seen in Robert's answer . But after comparison it is evident that these model-based predictions slightly deviate from my observed means that I calculate from my raw data, as you would expect from a prediction of a trend taking into account the random effects and interactions. So my primary question here is whether these predictions are at all valuable when discussing my results (i.e. under what circumstances one would refer to them/graphically depict them) or whether that is not their typical purpose, and I should stick to the observed means for discussion. Cheers for any help.


I am writing a function that is recieving a folder path as an arguemnt. I want her to add into a dictionary what's inside the folder (like dir in CMD)  How can I do this ?  Thank you in advance, Iliya


I have a multiple entry 90 days Schengen visa (category C) from 15 March 2014 till 21 Dec 2014.    With this visa I entered The Netherlands on 4 April 2014 and left there on 13 April 2014.    I am planning to re-enter The Netherlands on 19 Dec 2014 and leave there for London (I have a valid UK visa as well) on 21 Dec 2014, at 7 am from Amsterdam.    Am I permitted to stay in The Netherlands on 21 Dec 2014 or should I leave the country on 20 Dec evening itself?


Chebyshev Polynomials and Primality Testing

Let $T(n,x)$ be the nth Chebyshev polynomial of the first kind and let $U(n-1,x)$ the $(n-1)$th Chebyshev polynomial of the second kind. Would any one kindly help show that   1) $n$ is prime iff $T(n,x)$ is irreducible in $\mathbb{Z}[x]$.  2) $n$ is prime iff $U(n-1,x)$, expressed in powers of $(x^2-1)$, is irreducible in $\mathbb{Z}[x]$.   Many Thanks!!    No "ordering" is implied here. The wording of the question was done in similar fashion  as any question in any math/research question. I do not see how a person who is asking for help would be ordering people to help.   Any way back to the topic,  For the first part of the question, I noticed that if n is prime, then T(n,x) satisfies  Eisenstein's Irreducibility Criterion. But I am not sure how to show if T(n,x) is irreducible then n is prime.


I have a number of domains that I need to match on different websites. These websites are hosted on virtual machines that run on a dedicated server in the office where I work. The connection with the outside is on a single network interface (the only public IP), that is that of the router. Network traffic management takes place on a server running Zentyal 6.2 located in a DMZ. The goal would be to direct the various domains to the external IP and then make sure that they reach the VM with the corresponding site (each is configured with its fixed IP accessible to the LAN). Here are the things I've already tried with no success:  I redirected each domain on the IP specifying a port which I then forwarded to the corresponding VM (port forwarding). ex:  external_ip:15000 -> 10.1.1.1 (vm with site 1)  external_ip:16000 -> 10.1.1.2 (vm with site 2) I have configured the DNS of the domains on the external IP and I have made a port forwarding of all traffic to port 80 (or 443) of the VM; this solution is not good because I was unable to choose which VM to direct traffic to. I have configured the DNS of the domain as above but I have tried to use the Zentyal server as "local DNS server", it did not work but I don't know if because I have configured it wrong or simply because it is not a viable possibility.  The websites are of different nature (django sites, nextcloud, ...). I have read about the possibility of using Apache VirtualHosts but I have no idea how to use them in my case.


How to swap two values of single column in MySQL?

This in not a duplicate of this . I want to swap values vertically while in other question swap is horizontally.  I have table Products:  id  |   holder_id ---------------  1   |   2        2   |   2    3   |   13   4   |   13   5   |   1        6   |   12   7   |   16       8   |   20   --------------   Where holder_id is reference to User id. And table conversations:  id  |   user1   |   user2   |   product1    |   product2     ------------------------------------------------------- .. 2   |   12      |   2       |   6           |   2     What I want is to have a single statement to swap holder_id's for two products by conversation id. So for conversation id 2 it should look like this:  id  |   holder_id ---------------  1   |   2        2   |   12   3   |   13   4   |   13   5   |   1        6   |   2    7   |   16       8   |   20   --------------   So now the holder_id's for id 2 and 6 are swapped.  I have tried:  UPDATE products as p INNER JOIN conversations as c ON p.id=c.product1 SET p.holder_id=c.user2 WHERE c.id=2;   and with this I manage two do this:  id  |   holder_id ---------------  1   |   2        2   |   2   //still have to change this 3   |   13   4   |   13   5   |   1        6   |   2   // changed this 7   |   16       8   |   20   --------------   Now I have to do onother join to same table and I cant understand how to do that.


Remainder form of Taylor polynomial at $x_0$: $ \frac{1}{n!}f^{(n)}(x_0 +\theta(x-x_0))(x-x_0)^n$ with $\theta \to \frac{1}{n+1}$ as $ x \to x_0$

If the function $f: \mathbb R \to \mathbb R$ is $n+1$ times differentiable at $x_0$ and $f^{(n+1)}(x_0) \neq 0$, then a form of the remainder in Taylor's Formula is supposedly   $$r_n(x_0;x) = \frac{f^{(n)}\big(x_0 +\theta(x-x_0)\big)}{n!}(x-x_0)^n,$$ where $ 0< \theta < 1$ and $\theta = \theta(x)$ approaches $\frac{1}{n+1}$ as $x$ approaches $x_0.$  How would one derive this?  This seems quite strange to me.   For example, taking $f(x) =e^x$, the normal Taylor expansion for $n=2$ at $0$ would have the form  (Lagrange Remainder): $$e^x = 1 + x + \frac12x^2 +\frac{1}{3!}e^{\xi}x^3,$$ but in this case it is   $$e^x = 1 + x + \frac12x^2 +\frac{1}{2!}e^{\theta(x)}x^2$$.   The properties of $\theta$ do not make much sense. Am I missing something?


Notify when my question has been linked from another question

Sometimes a question I ask will get answers that don't help me, or maybe it doesn't receive any answers at all.  How about making a notification when somebody links to my question?   It could be something like this:     New information regarding your question might be available at {link}   It might help me getting an answer from related questions that weren't there when I first asked the question.


Why, when rounding, do we round 5 up to 10?

If we cut 10 in half, then we get 5. This means two 5s makes 10, meaning, 6, 7, 8, 9, and 10, are the remaining 5 numbers that make it up. So why do we round up 6 numbers? It's such a small thing but it annoys me so much.


Increasing system text size only makes comment text bigger

In the android app, I'd love for pinch-zoom text to be supported, but that's a . Rather than gripe about that, I just went to increase the system text size. Alas, this only makes the comment text easier to read, not the question or answer text. Running ICS 4.0.4 on a Samsung Galaxy tab 7. Screen captures With all system text set to normal size, the app looks like this:  After setting system text to large, the comment text gets bigger but not the question or answer text:


Why the Download Pages of our products are not indexed by Google?

I have a question about pages indexed, hope you can help me out, thank you in advance.   Recently, we found our French site's two download pages are not indexed by Google. The URL of the French site is: www.imobie.fr, the two non-indexed pages are:    and        Our website is not a new site, and the two pages always rank well in Google for several years, because the organic keywords are brand related, like AnyTrans Download or PhoneRescue Download, or just search AnyTrans or Download. Recently, we found the two pages' organic traffic declined sharply and then found they had disappeared from Google SERP, and they are not indexed by Google.   Then we checked Google Webmaster tool, in the Coverage > Crawled – currently not indexed found the two pages, then submitted them to Google for index yesterday, and found they are still not indexed by Google today. And the Google Analytics shows the organic traffic started to decline sharply from Aug.27th.    About this problem, we had tried the following methods,   Checked the two pages have “no index” tag in the page source – No  Checked robots file and see if we blocked the two pages from crawling - No  Checked the two pages' re=canonical tag and see if they are linked to the wrong pages – No  Checked if the pages for mobile phones has “no index” tag (Because our products are desktop software, for mobile users, we designed some pages to convert mobile users, only work for mobile users. Normally, we add “no index” to block them from Google crawling)  - Yes, they have.  Checked “Remove URLs” to see if we removed the two pages from google SERP by mistake – No.  Submit the two pages to Google via URL Inspection, but they are still not indexed.    So far, the pages are still not indexed by Google. And I just searched site:imobie.fr/anytrans/ download in Bing and yahoo.co.jp, I found I can find  in bing, but can’t in Yahoo. Therefore, I want to know why our pages are disappeared from Search engines’ SERPs, and not indexed, and how to make them indexed again. If possible, also hope you can check if the two pages have any not-friendly codes in the page source.


Incompatibility between fontspec and graphicx (bug of XeTeX)

I got a weird problem with the  package and the  package. Let's see the MWE first.  %!TEX program = xelatex \documentclass{article} \usepackage{graphicx} \usepackage{fontspec} \setmainfont{Times New Roman} \newfontfamily\test[AutoFakeBold = 5]{Times New Roman} \begin{document} \test Test \textbf{Bold Test}  \includegraphics[scale = 0.1]{photo}  Words that shouldn't be bolded. Even if \textmd{textmd-ed}. \end{document}         In the preamble, I loaded the graphicx package and the fontspec package, then I set Times New Roman as the default font of the text as well as the font of the test command. In the definition of \test, I enabled AutoFakeBold. In the document body, between the two chains of text, I inserted a photo with the \includegraphics command.  It's a normal manuscript, except that AutoFakeBold was set to 5 to make the abnormal output more remarkable. After the compilation, however, the later line of text presented an unexpected output. That is, this line of text shouldn't be bolded.  Even more surprising is that, if one   cancel the option passed to \includegraphics, or put some more text after \textbf{},   the problem will go away.  I suspect the problem lies in the FakeBold mechanism of the fontspec package and/or the key-val mechanism of the graphicx package, but unfortunately, I don't read LaTeX3 codes, so I cannot locate it.  Maybe an issue should be posted to fontspec or graphicx, but before that, could someone provide me a quick fix to this problem?    EDIT 2015/01/05  Thanks to the help of qingkuan@bbs.ctex.org, it seems to be a bug of XeTeX. See the new MWE.  % !TeX program = xetex  \font\x="[cmunrm.otf]" \font\bx="[cmunrm.otf]:embolden=5;"  \x Test {\bx Bold Test} \XeTeXpicfile "example-image.png"  width 1cm\relax Words that shouldn't be bolded.   \tracingoutput=1 \showboxbreadth=\maxdimen \showboxdepth=\maxdimen  \bye         I made a ticket on  and hope this will be fixed soon.


Why does it say (in python) "UnboundLocalError: local variable 'yes' referenced before assignment" when I already defined the variable?

This is my code:  from random import randint  ant1 = 1 ant2 = 2 ant3 = 3 ant4 = 4 cntNum = 0 no = 0 yes = 0  def antMove(antNum):     randomNum = randint(0,3)     if randomNum == antNum:         yes += 1     else:         print("No")     while cntNum < 20:     antMove(ant1)     antMove(ant2)     antMove(ant3)     antMove(ant4)     cntNum = cntNum + 1  if cntNum == 20:     print(yes)


Buying a Canon eos 2000d.  Building 2 soft light box with some white fabric and cheapo led strips with some dimming circuit.  Building a white paper desk for background  i have some photoshop and photograpy skills  Could i shot decent product photos with those equipment.  My target quality is this   thanks for your input


Equivalent conditions for continuous differentiability

Suppose I have a bounded open set $\Omega$ in $\mathbb{R}^n$; suppose that I have a map $f:\bar{\Omega}\to \mathbb{R}^m$ which is of smoothness class $C^1$ on $\Omega$ and the derivative $D(f|_{\Omega}):\Omega\to \mathcal{L}(\mathbb{R}^n,\mathbb{R}^m)$ can be extended to a continuous map on $\bar{\Omega}$. Is it true that $f$ is then of class $C^1$ on $\bar{\Omega}$? (Meaning that there is an extension of $f$ to a $C^1$ function defined on an open subset of $\mathbb{R}^n$ containing $\bar{\Omega}$.) I have proven the converse holds, but cannot prove this direction. I would like to avoid using the Whitney Extension Theorem, as I believe this is overkill; my "intuition" tells me that there should be some kind of partition of unity argument. The reason I would like the above to be true is so that I can finish proving $$ C^k(\bar{\Omega};\mathbb{R}^m) = \{ f\in C^k(\Omega;\mathbb{R}^m) : f\text{ can be extended to a }C^1 \text{ map defined on an open set containing }\bar{\Omega}\} $$ is a Banach space with the $C^k$ norm. Edit: This question is answered .


How can I "watch" a file for modification / change?

I would like to invoke my chrome or firefox browser when a file that I specify is modified. How could I "watch" that file to do something when it gets modified?  Programmatically it seems the steps are.. basically set a never ending interval every second or so and cache the initial modification date, then compare the date every second, when it changes invoke X.


Can I try to trip with the Maneuvers (Strikes) of a Crusader?


I am working on iPhone application.i want to check the application in between the development period? Is there any way by which i can check my application on IPhone device with out registering and paying 99$ to Apple? Please suggest me if there is any way available for that??


How to go about learning to program in Tex?

I have been using Tex for a few years now and enjoyed the work of others (e.g., ctan packages, templates, styles). My question sees to practical code to learn from. What would be a good primer, or project to study? For example I looked at ClassicThesis.sty. In order to actively contribute I would like to know how to go about.


Let $a = \liminf x_n$, $b = \limsup x_n$. If $\lim (x_{n+1} - x_n) = 0$ then every element of $(a,b)$ is a subsequential limit of $(x_n)$

I'm fixing an arbitrary $x$ in $a<x<b$ and I must prove that $x$ is the limit of a subsequence of $(x_n)$. I have a theorem that says that $x$ is a subsequential limit of a sequence $(x_n)$ iff every interval $(x-\epsilon, x+\epsilon)$ containts infinitely many terms of $(x_n)$. I also know that $a$ and $b$ are the smallest and largest subsequential limits of $(x_n)$.  I don't know where to go from here.


I'm a second year undergraduate student in Physics looking for a good textbook(s)/resource(s) to prepare me for my first Quantum Mechanics Class

I recently signed up for a Graduate Quantum Mechanics class at my University for the Fall of 2021 and after doing some review of the notes that the professor made available to me, I'm afraid I will be a little overwhelmed in the class. This is my first class in Quantum Mechanics although I have taken Modern Physics (giving me some very non-formal introduction to Quantum Mechanics) and wanted to know what are the best resources for some self-study during the summer before I start the class. I'm interested in learning the notation, and motivation behind QM while hopefully gaining some fluency in the Linear Algebra that will be involved.


The following method not returning any value (true or false).  \Drupal::service('path.matcher')->isFrontPage();   How to check if the page is front or not?


Do class/struct members always get created in memory in the order they were declared?

This is a question that was sparked by 's answer . Suppose I declare a class/struct like so: struct {      char A;     int B;     char C;     int D; };  Is it safe to assume that these members will be declared in exactly that order in memory, or is this a compiler dependent thing?  I'm asking because I had always assumed that the compiler can do whatever it wants with them. This leads into my next question.  If the above example causes memory alignment issues, why can the compiler not just turn that into something like this implicitly: struct {      char A;     char C;     int B;     int D; };  (I'm primarily asking about C++, but I'd be interested to hear the C answer as well) Related topics


Blender texturing of object is not correct

I am trying to render a simple obj model using blender. However, upon importing the obj model some of the textures are not showing. In the material properties I could see the multiple materials being assigned to the mesh. The zip file contains a screenshot for this.  I tried loading the model using Microsoft 3D builder as well as an online obj model viewer (3dviewer) and they had no issues at all displaying correct textures.  The zip file contains a screenshot for 3Dviewer.  This is my first time using blender and I am confused why a simple operation of loading an obj model is going wrong in blender. Any help in debugging this is appreciated.  The zip file also contains the 3D model itself.    Thanks!


Define a new block environment in LaTeX beamer

I have two kinds of examples in my document. I want to use different colors, say, red and blue. This is what I am doing now.  \documentclass[]{beamer} \usetheme{Madrid} \begin{document}  \begin{frame} \frametitle{Test} \setbeamercolor{block title}{fg=white,bg=red!75!black} \begin{block}{First Kind Example} This is example of the first kind. \end{block} \setbeamercolor{block title}{fg=white,bg=blue!75!black} \begin{block}{Second Kind Example} This is example of the second kind. \end{block} \end{frame}  \end{document}   I know this is kind of stupid. I want to define two new block environments, one for each color, so I don't need to use setbeamercolor every time I use them.   \begin{block1}{First Kind Example} ... \end{block1} \begin{block2}{Second Kind Example} ... \end{block2}   I know I need to define these two new environments in the preamble, but don't know how. Thanks for the help.  By the way, what is a good reference on these kinds of tricks in LaTeX/beamer? Any recommendations?


Database transaction log growth who is the cuplrit?

There are abundant information on how to shrink a growing Transaction log, from frequent log backups, to changing the RECOVERY from FULL to SIMPLE and truncate. A daily background job takes care of this process and it's working fine. By now, most people know how and why Transaction Log works. There is a complete explanation .          I have a misbehaving application that, somehow, create a growing transaction log by not releasing, not sure if it's not committing or not closing or what, at the end of the (whatever) action.      It doesn't look like there is data loss or inconsistencies and not any unusual situation on the DB.      Upon restarting SQLSERVER show the database in 'recovery mode' for a while and then back to normal.      Doing DBCC LOGINFO, shows over 100 entries, all of them with 'Status=2' so I understand, they are in use. Interesting but on some entries, the 'filesize' is even larger that the Database itself!        The subject database on SELECT name,log_reuse_wait_desc,recovery_model_desc FROM sys.databases show log_reuse_wait_desc as 'NOTHING' and recovery_model_desc as 'FULL'       My question is: Is there any method, documented or not, to 'read' the log file and find what table, application, data or whatever info is on the VLF to help finding the culprit application?


String str = 'hellotest'; String qry = 'select id,Products__c from Account where End_Date__c > :system.today() and Start_Date__c < :system.today() and IsValid__c = true and Approved__c =' + '\'' + 'Yes' + '\'';         //order by createddate desc         if(!str.equals('NoPromo')){             qry = qry + ' and teststr__c = :str' ;             qry = qry + ' and Offer_Type__c ='  + '\'' + 'Promo Code Campaign' + '\'';         }             qry = qry + ' order by createddate desc';             system.debug(qry);                 for(Account pc: Database.Query(qry)){}   When i am trying to execute the above logic it is throwing the error      System.QueryException: unexpected token: '('   Can someone please help me where i am doing wrong here


Backup and restore Android app data with Terminal Emulator (rooted)

What is the right or the best way to backup and restore android app data by terminal emulator in a rooted phone?  su -c cp -r /data/data/the.app.id /sdcard/the/backup/directory can copy the app data, but copying them back will cause some problems. For example, the owner and group of them are not correct, permissions are not right, only root can access them.  I've searched for a while and got some solutions that I don't want. adb backup the.app.id needs a computer. Some apps cannot access sdcard, so switching to it then copying is not possible. Also, to copy it, iterate through the whole directory and chmod with root takes a lot of time and may not work.  If the question needs more explanations, please tell me by comment. Thanks for reading or answering this.


I read that it was known to Euler that $$\sum \frac{\zeta(n) -1}{n} = 1- \gamma$$, but I cannot find a proof of this and am curious how he obtained it. I first tried messing with the definition of $\gamma$, given as the limiting difference between the partial sums of the harmonic series and the natural log, but could not connect it to the zeta function. From whichever method is used to obtain the result, could we likewise obtain $\sum \frac{\zeta(2n) -1}{2n}$ or $\sum \frac{\zeta(2n+1) -1}{2n+1}$?  Could we somehow begin with the result that $\sum (\zeta(n) -1) = 1$?


Unnecessary repetition of "is" in spoken English

Over the past few years I have often heard people repeat the word "is" unnecessarily, for example, "My concern is, is that by going backwards we will throw a spanner in the works and that momentum will be halted." (Sir Michael Wilshaw, Chief Inspector of Schools, Radio 4 Today Programme, 9th September 2016.)  Sometimes, as in the above example, there is a discernible pause between the two words, and sometimes there is none.  Has this phenomenon been remarked upon and does it have a name? If not, may I suggest "isisism".


Identify the cause of BSOD from a minidump file


How can I search Google for a negative number?

It only rarely happens, but once or twice I've found it desirable to be able to search the web for a set of search terms that includes a negative number. Unfortunately there doesn't seem to be any obvious way to do this.  Simply including the number, e.g. -9 in the search terms will cause Google to exclude all results containing the number 9, since it treats - as an exclusion operator. Alone, a search for -9 .  Similarly, enclosing it in quotes "-9" returns , not -9. But I need to disambiguate them: in my particular search, results including 9 are useless while I actually need results for -9.  A  indicates that even Google's own employees don't know how, or if, this can be done.  Is it even possible to do this at all?


Is there the way to generate new Koblitz curves, over $\mathbb F_{2^n}$ and $\mathbb F_p$?  The  says:     The recommended parameters associated with a Koblitz curve were chosen by repeatedly selecting parameters admitting an efficiently computable endomorphism until a prime order curve was found.   What does "efficiently computable endomorphism" mean? Maybe it means that trace of the Frobenius map should be equal 1? I am confused about all the Frobenius maps, endomorphisms, traces, etc.  So, is there the way to generate Koblitz curves, or find efficiently computable endomorphisms?


What do you call someone who starts arguments for their own satisfaction?

I was wondering if there is a word used to describe someone who starts arguments just because they get enjoyment/satisfaction out of it. And I don't mean a friendly debate I mean actual arguments, like a fight. I feel like there is a word for it but I can't think of it and if there is no word then I am going to make one for it :). P.S. "Devil's Advocate" is not the word I am looking for.


GNU `find` issue : `find -name` isn't recursive when pattern is found in current directory

I have a test tree that goes like this :  user@host :~/test/ $ tree . └── 1st     ├── 1st.json     └── 2nd         ├── 2nd.json         └── 3rd             └── 4th                 ├── 4th.json                 └── 5th                     └── 5th.json  5 directories, 4 files    And I get this behavior from find :  user@host :~/test/ $ find . -name *.json ./1st/2nd/3rd/4th/4th.json ./1st/2nd/3rd/4th/5th/5th.json ./1st/2nd/2nd.json ./1st/1st.json    user@host :~/test/1st $ find . -name *.json ./1st.json    user@host :~/test/1st/2nd $ find . -name *.json ./2nd.json    user@host :~/test/1st/2nd/3rd $ find . -name *.json ./4th/4th.json ./4th/5th/5th.json    user@host :~/test/1st/2nd/3rd/4th $ find . -name *.json ./4th.json    user@host :~/test/1st/2nd/3rd/4th/5th $ find . -name *.json ./5th.json    The command seems to be recursive only if find doesn't find filenames that match the pattern in the current directory.  Removing . in the command gives the same output each time.  Is it normal behavior. And in both cases, is there a way to modify this and how ?  PS : Also =>  user@host :~/test/1st $ find -mindepth 0 -name *.json ./1st.json user@host :~/test/1st $ find -mindepth 1 -name *.json ./1st.json user@host :~/test/1st $ find -mindepth 2 -name *.json user@host :~/test/1st $ find -mindepth 3 -name *.json user@host :~/test/1st $ find -mindepth 4 -name *.json user@host :~/test/1st $ find -mindepth 5 -name *.json


How to set Google+ photos to be Public-Unlisted (as you could do with PicasaWeb)?

Previously, if I uploaded photos from Picasa to PicasaWeb, I could specify them as Public but Unlisted. So you had to have the link to view them but no login was required.  I don't see that option now that Picasa uploads to Google+.  Any ideas?


Does brother-in-law count as immediate family member for UK visa?

In the online visit visa application for the UK, I have to add immediate family members. My sister's family lives there. Do I have to add her husband too as an immediate family member?


How to print a field value in page front tpl file?

I'm trying to load a field value (machine name: field_theme_image) from a content of node value 3, in "page--front.tpl.php".  <?php   $node=node_load(3);   print $node->field_theme_image[$node->language][0]['uri']; ?>   Using the above code I'm not getting full URL value. Please see the image below. I can see the path value in Devel themer.


Why doesn't grep -r also look in subdirectories when I search with a glob?

Grep with -r was not working for me.  I then made a test situation.  The directory /home/den/backup now contains a file with the word washer in it.  I also made a subdirectory within /home/den/backup.  In that directory a file contains the word washer.  The following should return two hits at  /home/den/backup/great.txt and /home/den/backup/aaa/info.txt  If I issue   grep -r "washer" /home/den/backup/*.*   the result is one hit.  If I issue  grep -r "washer" /home/den/backup/aaa/*.*   the result is one hit.  Shouldn't the first one have also found the second one, which is in one if its sub-directories?


What is the way to separate range and pass the array to the function?

I have array of attachmentList and  if I do  len(attachmentList)    the result is 199930;  and I would like to send 999 elements each time to  api_request(attachment) function  so pseudo code will be like this  count=0 for (i=0,i<len(attachmentList),i++)      count++      if count=999:        api_request(attachmentList[i-999:i])        count=0   What is the way to write for loop or there is another solution for that.


I know that  $$\sum^n_{i=1}i^2=\frac{1}{6}n(n+1)(2n+1)$$ and  $$\sum^n_{i=1}i^3=\left(\sum^n_{i=1}i\right)^2.$$ Here is the question: is there a formula for  $$\sum^n_{i=1}i^4.$$


Angular equation for Schrödinger's equation in 3D

In Griffith's book, section 4.1.2, the angular equation for Schrödinger equation in 3D is expressed as $$\sin\theta \frac{\partial}{\partial \theta}(\sin \theta \frac{\partial Y}{\partial\theta})+\frac{\partial^2 Y}{\partial \phi^2}=-\ell(\ell+1)\sin^2\theta Y.$$ Using the separable solutions $Y(\theta,\phi)=T(\theta)P(\phi)$, he eventually arrived at $$\frac{1}{P(\phi)}\frac{\partial^2 P(\phi)}{\partial \phi^2}=-m^2$$ $$\frac{\partial^2 P(\phi)}{\partial \phi^2}=-m^2P(\phi)$$ where $m$ is a constant.  He then went on to say that the solution for $P(\phi)$ is $$P(\phi)=Ae^{im\phi}$$ instead of the usual $$P(\phi)=Ae^{im\phi}+Be^{-im\phi}$$ by saying that he allows $m$ to be negative.  How are the above two solutions equivalent? For a particular value of $m$, his solution to $P(\phi)$ will always be lacking an extra term $Be^{-im\phi}$, no matter whether $m$ is positive or negative.


Evaluation of $\lim_{x\rightarrow \infty}\sqrt{x^2+x+1} -\lfloor \sqrt{x^2+x+1 }\rfloor\;,$

Evaluation of $\displaystyle \lim_{x\rightarrow \infty}\sqrt{x^2+x+1} -\lfloor \sqrt{x^2+x+1 }\rfloor\;,$ where $\lfloor x \rfloor$ represent floor function of $x$.  $\bf{My\; Try}::$   $\bullet\; $If $x\in \mathbb{Z}\;,$ and $x\rightarrow \infty\;,$ Then $x^2<x^2+x+1<x^2+2x+1$  So $x<\sqrt{x^2+x+1}<(x+1)\;,$ So $\lfloor x^2+x+1 \rfloor = x\;,$ bcz it lies between two integers.  So $\displaystyle \lim_{x\rightarrow \infty}\left(\sqrt{x^2+x+1}-x\right) = \lim_{x\rightarrow \infty}\left(\sqrt{x^2+x+1}-x\right)\cdot \frac{\left(\sqrt{x^2+x+1}+x\right)}{\left(\sqrt{x^2+x+1}+x\right)}$   So $\displaystyle \lim_{x\rightarrow \infty} \frac{x+1}{\sqrt{x^2+x+1}+x} = \frac{1}{2}$  $\bullet\; $ If $x\notin \mathbb{Z}$ and $x\rightarrow \infty\;,$ Then How can i solve the above limit in that case,  Help me, Thanks


Possible Duplicate:    Based on , is there a rule of thumb when a number should be spelled out? These examples are easy:  I have two brothers. It's exactly 823 miles to New York.  But do I have 15 minutes of fame, or fifteen minutes of fame? Edit:   asks how the practice of spelling out numbers originated; I'm looking for specific guidelines.


I have a 2 TB disk which I use for data. Running Ubuntu 14.04 from another physical drive and Windows from a third physical drive.  On the 2 TB drive I have (or, had...) one ext4 partition filling out the entire drive.  When booted into Windows 7, and entering its disk tool, I was told that the drive had no partition table (?), giving me the options of gpt and something else, before even allowing me in to the tool. Thinking it was referring to a fourth physical drive in the machine, which did indeed not have any partitions on it, I foolishly opted for gpt, but did nothing else to the drive (didn't create any partitions, etc.).  Back in Linux, when I run gpart, only what seems to be two old (now unused) partitions are found:  $ sudo gpart /dev/sdc  Begin scan... Possible partition(Windows NT/W2K FS), size(0mb), offset(228937mb) Possible partition(Windows NT/W2K FS), size(25497mb), offset(1266234mb) End scan.  Checking partitions... Partition(OS/2 HPFS, NTFS, QNX or Advanced UNIX): primary  Partition(OS/2 HPFS, NTFS, QNX or Advanced UNIX): primary  Ok.  Guessed primary partition table: Primary partition(1)    type: 007(0x07)(OS/2 HPFS, NTFS, QNX or Advanced UNIX)    size: 0mb #s(1) s(468863136-468863136)    chs:  (1023/254/63)-(1023/254/63)d (29185/97/1)-(29185/97/1)r  Primary partition(2)    type: 007(0x07)(OS/2 HPFS, NTFS, QNX or Advanced UNIX)    size: 25497mb #s(52219903) s(2593248336-2645468238)    chs:  (1023/254/63)-(1023/254/63)d (161422/62/1)-(164672/199/22)r  Primary partition(3)    type: 000(0x00)(unused)    size: 0mb #s(0) s(0-0)    chs:  (0/0/0)-(0/0/0)d (0/0/0)-(0/0/0)r  Primary partition(4)    type: 000(0x00)(unused)    size: 0mb #s(0) s(0-0)    chs:  (0/0/0)-(0/0/0)d (0/0/0)-(0/0/0)r   Also, fdisk doesn't seem to see it:  $ sudo fdisk -l [...] Disk /dev/sdc: 2000.4 GB, 2000398934016 bytes 256 heads, 63 sectors/track, 242251 cylinders, total 3907029168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disk identifier: 0x00000000     Device Boot      Start         End      Blocks   Id  System /dev/sdc1               1  4294967295  2147483647+  ee  GPT Partition 1 does not start on physical sector boundary.   And neither parted:  $ sudo parted -l [...] Model: ATA ST2000DM001-9YN1 (scsi) Disk /dev/sdc: 2000GB Sector size (logical/physical): 512B/4096B Partition Table: gpt  Number  Start   End    Size   File system  Name                          Flags  1      17.4kB  134MB  134MB               Microsoft reserved partition  msftres   Warning: Unable to open /dev/sr0 read-write (Read-only file system).  /dev/sr0 has been opened read-only. Error: Can't have a partition outside the disk!                              What am I missing? Is there any way I can recreate the lost partition?


Solve a linear system with more variables than equations

Suppose that, after a series of elementary row operations the augmented matrix of a linear system with variables $x_1$, $x_2$, $x_3$, $x_4$ is transformed into reduced row echelon form as follows:  $$\left(\begin{array}{cccc|c}1 & 0 & 0 & 1 & 0\\0 & 1 & 0 & 2 & 1 \\0 & 0 & 1 & 3 & 0 \end{array}\right)$$.  Can I solve the linear system as below?  Let $t$ be an arbitrary real number. Then solving each linear equation corresponding to the augmented matrix for leading variable and setting $x_4=t$, we get $x_1=-t, x_2=1-2t$, and $x_3=-3t$. Thus the general solution of the linear system is  \begin{align} x_1=-t\\ x_2=1-2t\\ x_3=-3t\\ \end{align}  where t is an arbitrary real number.


Which reference to 'mum' in the following text shouild be capitalised, and which not capitalised? I'm confused...  ...................................................................  What? Did you say you’d met a man? Mum…mum – crikey – really? Do tell. What’s he like? Never too late, mum, I’ve always told you that. I’ve also got news, but not as exciting as yours…wow!’ Jessica chose her words carefully. ‘Saffie, it’s not like that, really it isn’t.’ She heard giggles. ‘Come on, mum – what do you mean? You’ve fallen in love, haven’t you – admit it.’ Saffron giggled again. ..........................


What is the sort order when using conditional operators?

I wrote a bash script that processes a list of filenames (using glob expansion, as in for f in *) and then outputs a subset of this list to a file. Subsequently I read the content of this file into an array and perform a plain binary search for specific filenames using the obvious < and > operators for comparing strings.  Considering that I would like the script to work on as many different environments like Linux, MacOS, MinGW, ... (even though it uses things like [[ and stat which are less portable), my questions are:   Do I need to sort the file content (either with sort or additional bash code) or is the glob expansion always sorted - in every environment? Do the conditional operators use the same "sorting" as the expansion (or after sort)?  Would expansion or sort return file10.txt after file2.txt (in what cases?) but using conditional operators file10.txt would be before file2.txt ? What sort option would I  use to fix this? Are there any caveats if some of my filenames are in Unicode?   Are there any issues using specific versions of bash?   Does LC_COLLATE affect any of the above?     I obviously need the file content to match the sorting "method" of the operators in order for the binary search to work as expected...


Prove that $4$ is the only solution to $2+2$.

This question was featured on  and I haven't been able to find a proof. Can anyone help?


Which sentence is more grammatically correct?     He is being tried on what look like trumped-up charges.   He is being tried on what looks like trumped-up charges.


Photons are packets of electromagnetic radiation (wave) what about other particles?

Photons are packets of electromagnetic radiation (wave), what about other particles? Are other particles, say electrons, really just packets of waves?


Can I replace 27.5x2.25 tire with a hybrid/road tire?

I am new to cycling. I recently got Jamis Trail X with 27.5x2.25" tires. This is a bit hard (not easier) on city roads. I was thinking about replacing the tires with max 1.5" wide hybrid or road tires. I researched a little bit and learned that 27.5 is not actually 27.5 rim. It's 26.5" or 584mm in diameter. My question is, can I replace these tires with any 584 or 650b tires?


Sometimes comments are helpful enough to be considered answer.  What do you think about a button or something that allows to convert a comment into an answer?


"Has/Have/Had" as a main verb and auxiliary verb

I need help regarding the use of has/have/had both as a main verb and as an auxiliary verb.  In the sentence below, the word has acts as the main verb. I would normally follow it with the phrase "so do I."        Kenny has a car, and so do I.      On the other hand, the word has in the following sentence acts as an auxiliary verb. I would normally follow it with the phrase "so have I."        Kenny has bought a car, and so have I.      a) Are sentences 1 & 2 above correct? I'm under the impression that so do I is used when has/have/had is the main verb of a sentence, and so have/had I if it's an auxiliary verb in a sentence.  b) Does the verb has/have always need a supporting "auxiliary verb" (either implied or mentioned)? (e.g., Kenny has a car = Kenny does have a car.)


Downgraded MacOS to Mojave how do I tell the App Store to forget I ever installed things on Big Sur?

Of course when I say downgrade I just mean "wiped the drive entirely and installed Mojave from scratch" because it turns out that I had both software and hardware that just didn't work on Big Sur, but now the App Store does not seem to have any way for me to say "forget that I was ever on Big Sur" and I can't install apps I had installed before. Even free apps like The Unarchiver or MS Remote Desktop Client refuse to install and show a little cloud-download icon, with no way to say "please just reset yourself, I'm on Mojave, I need the Mojave versions of everything".  I tried Googling for this, but I can't seem to find a single page (either on the web or even just here) that explains how to actually fix this problem. Lots of pages that explain how to get the old version of MacOS itself through the App Store, lots of articles about getting older versions of iOS apps on older iPhones, but not a single result for how to tell the App Store to forget the "newer" version and instead pull the version appropriate for the OS that the App Store is running in... Is there a way to do this on a machine without backups made before the erase or upgrade?


High load average, when should I be worried?

I have a server which runs a few hundred processes simultaneously, most of them are idle, it is some sort of web crawler it sleeps between requests for various reasons.  So as a result, my load average is usually something like: 21.64, 27.05, 29.16  That's very very high right? But everything runs smoothly!  And my CPU consumption is something like (mpstat 60 1 output):  11:07:06 AM  CPU    %usr   %nice    %sys %iowait    %irq   %soft  %steal  %guest  %gnice   %idle 11:08:06 AM  all   34.82    0.00    4.16   10.70    0.00    0.31    0.00    0.00    0.00   50.01 Average:     all   34.82    0.00    4.16   10.70    0.00    0.31    0.00    0.00    0.00   50.01   So, since I'm not even running at 100% CPU usage I feel like I do not have a reason to be worried, or am I missing something? There is a slight delay when nginx is serving requests, but that's expected given the large number of queued requests, But I read somewhere that a load average higher than 1 is a cause for alarm, and I honestly don't see why that is.   So please advise.  Thanks


Will everything (downloaded fonts, files, apps etc) remains the same when I upgrade from one release to the next?

I'm planning to upgrade from Maverick to Natty, and to try out Unity, but I don't want to lose any settings, customizations and downloads in Maverick. I just want to know, if upgrading alter anything that I said earlier?   I don't want to start over with a clean, fresh Natty, and I hope I can keep all of my files and folders and settings in Maverick, and to have them in Natty after the upgrade. Is this possible? Should I use Update Manager to achieve this? And would all my compiz-settings be reset after I upgrade?   Sorry for too much questions, but I'm asking this because you know, in Windows, any version upgrade would require the disk to be reformatted. I hope Ubuntu is more convenient than that.


I am using Debian sid, hard drive formatted with ext4, running on linux 3.1  I remember on previous linux versions (maybe before 3.0), if I run out of memory, and swap is not enabled, programs will usually crash. This is perfect for my environment: simple web browsing with no critical operations. That is, if I accidentally run across a bad website which uses up too much memory, it just crashes without rendering my terminal unusable.  But in my current setup, the computer hangs with violent I/O throughput in the background. iotop reveals kswapd0 to be the culprit, which means it is due to swapping. After using swapon -s to determine any swaps that were enabled, I used swapoff -a to disable all swaps and swapon -s again to confirm that all swaps were disabled.  Then I tried maximizing my memory usage again. Alas, the behavior I expected didn't happen. Instead, kswapd0 tries over and over to swap out the RAM and fails as there is no swap space. Because it never gives up, my computer is locked in eternal I/O heavy freeze, bad for my disk's health.  Am I doing something wrong in trying to swapoff -a? Why is the behavior different than what it used to be (probably pre-3.0 times)?


I want to be able to set the height and width of my rectangles, as well as the angles. I have been trying the Rectangles Ovals Digitizing plugin, but I can't seem to make it do anything (besides turn on, I did figure that part out). I'm not finding any tutorials on how to use this plugin. I'm fairly new to QGIS, so I may be missing something blatantly obvious!   I'm running Essen 2.14.


How to get type of the badge (Bronze, Silver, Gold) from Data Explorer?

I was just curious who have the most Gold, Silver or Bronze badges but I can't find the field in Data Explorer that represents the type of the badge. Either it's missing or I can't find it.   So, how to get the type of the badge in DE?


Why isn't minimal sigma-algebra simply the set containing all countable unions and complements

For $X$ a set and $A\subset X$ the sigma-algebra generated by $A$ is $$\sigma(A)=\bigcap\{\Sigma: \text{$\Sigma$ $\sigma$-algebra s.t. $A\subset\Sigma$}\}.$$ However why can' t we simply say $$\sigma(A)=\{\text{all countable unions and complements of elements of $A$}\}\cup \{\emptyset,X\}?$$  What would be a good counterexample?


How can I select top and bottom vertices at the same time in top view?

I start with a cube, then go into top view. I'd like to change its shape into something else but when I press G, only the top vertex is grabbed, and it changes my square into some weird triangle. I'd like to know if there is a way, without leaving top view, to grab both the top and bottom vertices of the square. It seems like a common problem and I can't figure it out. Should I instead be starting with a plane then adding thickness later?


Can't start MongoDB , mongod is always stop/waiting

I try to run v2.6.10 on Ubuntu 16.04 server:  sudo service mongod start   And get the result:  mongod start/running, process 67725   But when I check the status I get:  mongod stop/waiting   The content of log:  2017-09-10T07:47:16.528+0200 [initandlisten] MongoDB starting : pid=5493 port=27017 dbpath=/data/db 64-bit host=ns1 2017-09-10T07:47:16.529+0200 [initandlisten] db version v2.6.10 2017-09-10T07:47:16.529+0200 [initandlisten] git version: nogitversion 2017-09-10T07:47:16.529+0200 [initandlisten] OpenSSL version: OpenSSL 1.0.2g  1 Mar 2016 2017-09-10T07:47:16.529+0200 [initandlisten] build info: Linux lgw01-12 3.19.0-25-generic #26~14.04.1-Ubuntu SMP Fri Jul 24 21:16:20 UTC 2015 x86_64 BOOST_LIB_VERSION=1_58 2017-09-10T07:47:16.529+0200 [initandlisten] allocator: tcmalloc 2017-09-10T07:47:16.529+0200 [initandlisten] options: { config: "/etc/mongod.conf", net: { bindIp: "127.0.0.1", port: 27017 }, storage: { dbPath: "/data/db", journal: { enable$ 2017-09-10T07:47:16.529+0200 [initandlisten] exception in initAndListen: 10309 Unable to create/open lock file: /data/db/mongod.lock errno:13 Permission denied Is a mongod ins$ 2017-09-10T07:47:16.529+0200 [initandlisten] dbexit: 2017-09-10T07:47:16.529+0200 [initandlisten] shutdown: going to close listening sockets... 2017-09-10T07:47:16.529+0200 [initandlisten] shutdown: going to flush diaglog... 2017-09-10T07:47:16.529+0200 [initandlisten] shutdown: going to close sockets... 2017-09-10T07:47:16.529+0200 [initandlisten] shutdown: waiting for fs preallocator... 2017-09-10T07:47:16.529+0200 [initandlisten] shutdown: lock for final commit... 2017-09-10T07:47:16.529+0200 [initandlisten] shutdown: final commit... 2017-09-10T07:47:16.529+0200 [initandlisten] shutdown: closing all files... 2017-09-10T07:47:16.529+0200 [initandlisten] closeAllFiles() finished 2017-09-10T07:47:16.529+0200 [initandlisten] shutdown: removing fs lock... 2017-09-10T07:47:16.530+0200 [initandlisten] couldn't remove fs lock errno:9 Bad file descriptor 2017-09-10T07:47:16.530+0200 [initandlisten] dbexit: really exiting now


How to remove bounty completely using console commands?

I have created problems at many places in Skyrim thinking I would use bend will shout and now I want it to get cleared.  The problem is I don't have saved games and set.playergoldcrime 0 is not working it is just reducing the bounty on me.  How can I remove the bounty completely?


public static void main(String[] args) throws IOException {     RbnRunner runner = new RbnRunner();     runner.run();  }  public void run() throws IOException {      System.setProperty("webdriver.chrome.driver", "/Users/me/samples/Adam_milford/src/chromedriver");      WebDriver driver = new ChromeDriver();   but when I want to init a headless selenium driver instead of Chrome driver, the code failes:  public static void main(String[] args) throws IOException {     WebDriver driver = new HtmlUnitDriver();   why is that?  Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/http/impl/conn/PoolingClientConnectionManager     at com.gargoylesoftware.htmlunit.HttpWebConnection.createHttpClient(HttpWebConnection.java:536)     at com.gargoylesoftware.htmlunit.HttpWebConnection.getHttpClient(HttpWebConnection.java:500)     at com.gargoylesoftware.htmlunit.HttpWebConnection.setUseInsecureSSL(HttpWebConnection.java:711)     at com.gargoylesoftware.htmlunit.WebClient.setUseInsecureSSL(WebClient.java:1096)     at org.openqa.selenium.htmlunit.HtmlUnitDriver.createWebClient(HtmlUnitDriver.java:263)     at org.openqa.selenium.htmlunit.HtmlUnitDriver.<init>(HtmlUnitDriver.java:129)     at org.openqa.selenium.htmlunit.HtmlUnitDriver.<init>(HtmlUnitDriver.java:172)     at org.openqa.selenium.htmlunit.HtmlUnitDriver.<init>(HtmlUnitDriver.java:168)     at RbnRunner.run(RbnRunner.java:40)     at RbnRunner.main(RbnRunner.java:28) Caused by: java.lang.ClassNotFoundException: org.apache.http.impl.conn.PoolingClientConnectionManager     at java.net.URLClassLoader.findClass(URLClassLoader.java:381)     at java.lang.ClassLoader.loadClass(ClassLoader.java:424)     at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)     at java.lang.ClassLoader.loadClass(ClassLoader.java:357)     ... 10 more


How can we prove that $\int_0^\infty e^{-ix}x^{s-1} \ \mathrm{d}x = i^{-s}\Gamma(s)?$

I have seen   $$\int_0^\infty e^{-ix}x^{s-1} \ \mathrm{d}x = i^{-s}\Gamma(s)$$ in a few posts regarding Mellin tranforms or a few difficult integrals. How can we prove this equality? I assume it can only be proven by residue theory.


Why can't helicopters reach mount everest?

Is there a reason why people can't just take the helicopter to mount Everest? Why is it that helicopters can't reach that high?


I need your help,  How can I dead center a div within another div, both horizontally and vertically on page?  So far, I have managed to center my div horizontally.  Here's the HTML markup in question  <!DOCTYPE html>

                     some text here


If $a+b+c=1$ and a,b,c ＞0 prove $\dfrac{b^2}{a+b^2}+\dfrac{c^2}{b+c^2}+\dfrac{a^2}{c+a^2} \geqslant \dfrac{3}{4}$

If $a+b+c=1$ and a,b,c＞0 prove $\dfrac{b^2}{a+b^2}+\dfrac{c^2}{b+c^2}+\dfrac{a^2}{c+a^2} \geqslant \dfrac{3}{4}$. I tried with CS Engel form,homogenization but ina anyway i can't prove inequality. Can someone helpp?


US passport holder visa to turkey fromega Germany

I am American visiting in Germany .. do I need visa to enter turkey ? If yes what are the process? Since I am American visiting in Germany. .  Thanks


At the end of Avengers: Infinity War, what is the live/dead ratio?

We all know that Thanos wants to wipe out half of the universe's lives.      At the end of Infinity War: He snaps his fingers and succeeds in  wiping half of the universe.    How consistent is Marvel with that information? Do only 50% of the  main cast gets wiped out?


Error code 0x803F7001 activating Windows inside Virtual Box

I had genuine Windows 7 and Windows 8, from some of which I have physical DVD boxes. Later it was upgraded automatically to Windows 10.  Recently I tried to make ISO with Media Creation tool, made ISO and install it into virtual machine within the same computer, I have original Windows 10. During installation it asked me for product key which I had none and answered "I have none".   Now inside Virtual Box I have activation problem. It says it can't activate and suggests to do something, including change product key. Inside properties of My PC of activated computer I see product ID which has different format and I can enter it into virtual machine.  Is it possible to overcome?


Clicking an url or a zip file in yakuake/konsole, opens gedit! How to change that?

The url was to a remote zip file, for example    xdg-settings get default-web-browser gives chromium-browser.desktop, so "any?" url should be opened at chromium, not GEdit...  My default zip opener in nautilus is "archive manager", not GEdit...  Even worse: in GEdit, it will not even download the file first, it will open inside GEdit (of course) as an uneditable binary file, and will still open it remotely, and if I try to save it seems to try to save remotely too (now that becomes a problem as I didnt intend to do that ever!) :(  What is happening? How can I fix it?  I am on Ubuntu 14.04, and the highest version of yakuake (the one I am using) on it is 2.9.9-1 to the date. Konsole also at latest 4.13.3.


Is there a way to shrink a Log File in SQL Server without affecting Point in Time Recovery?

My friend (who doesn't use stackoverflow) asked me a peculiar and interesting question just now.  Is there a way to "disconnect a Log file, or shrink a log file without affecting Point in Time Recovery"? as I quote his exact words. He is working against a live system, and somehow, the Log file has grown to 72GB  All I know is you can Delete a log file (as indicated in the snippet below from technet)  USE master; GO ALTER DATABASE AdventureWorks2012 REMOVE FILE test1dat4; GO   And Truncate it  DBCC SHRINKFILE(<log_file_name_Log>) BACKUP LOG <database> WITH TRUNCATE_ONLY DBCC SHRINKFILE(<log_file_name_Log>)   I am no SQL Server wiz, and from my experience which I have, I cannot help him - though this is something I want to know the answer myself -  Any advice?


Replace string in a line, where the line is inputed by a variable

I want to replace a string in a line of a document, with sed. Where the LINE Number value should come from a variable, $var.  I've tried:  sed '%ds/peer/md5/g' $var ./temp.txt   but it gives   sed: -e expression #1, char 1: unknown command: `%'   Also tried:  sed -e '"$var"s/peer/md5/g'-i ./temp.txt sed: -e expression #1, char 1: unknown command: `"'   Finally tried:  printf '%ds/peer/md5/g;\n' 80 | sed -f - ./temp.txt   which prints correctly, but I can't save the result file with output redirection (>) or -i command.


What's the technical explanation for gravity to exist inside a spacecraft in science fiction?

Specifically, spacecraft that are not obviously using centrifugal force to simulate gravity the way that the space station from 2001 does.


"undefined reference to" linker error while working with templates

I have a class Array  template <typename T> class Array : public SequentialContainer<T>{ public:     Array(Int size){local_vector.reserve(size);}     Array(std::initializer_list<T> initializer_list){         local_vector.assign(initializer_list);     }     virtual Boolean contains(T &object) const;     virtual Boolean contains(Container<T> &container) const;     virtual Int size() const;     virtual T &operator[](Int idx);     virtual T &get(Int idx);     virtual void set(Int idx, const T &object);     virtual Int indexOf(T &object);     virtual Iterator<T> iterator() const; };   All the methods are implemented like this in the Array.cpp file:  template <typename T> Boolean Array<T>::contains(T &object) const { //code }   If i try to use this Array class in a main.cpp file:  Array<int> c = {1, 2, 3, 4, 5, 6}; std::cout << c.[4] <<std::endl;   I am getting these linker errors:  undefined reference to `Array<int>::iterator() const' undefined reference to `Array<int>::contains(int&) const' undefined reference to `Array<int>::contains(Container<int>&) const' etc...   for every single method of the Array class. All the files are in my cmake file and should be compiled. Why I am getting this linker error? could someone explain me this please?


I'm using the listing package for displaying source code in my document. I want to use the minipage environment to avoid page breaks within the listing, but I don't want to write, at every listing,  \begin{minipage}{\linewidth} \begin{lstlisting} ... code goes here ... \end{lstlisting} \end{minipage}   I've tried to define a new environment, like so  \newenvironment{codeListing}{\begin{minipage}{\linewidth}\begin{lstlisting}}{\end{lstlisting}\end{minipage}}   for using it like this  \begin{codeListing} ... my code ... \end{codeListing}   What am I doing wrong?


is there any way to change host for a website without suffering from downtime?

I have a website with DNS pointing to my hosting account at ns1.a.com and ns2.a.com  I want to switch a hosting account (to ns1.b.com and ns2.b.com).   However if I simply change the DNS the site will be inaccessible until the change is complete, is there anyway to change host for a website without suffering from downtime?


Determine if this series converges or diverges. What test to use?

Say I have this series:  $$\sum_{n=1}^{\infty} \frac{n+3^n}{n+2^n}$$  I think I can compare it to $$b = \frac{3}{2}^n$$ which is a geometric series that diverges.  But where do I go from here? The issue is that the numerator and denominator both increase so I can't say that the original series diverges or not by Comparison Test. What else can I do?


I didn't know where can I start because it doesn't fit to any theories or formulas.  If $a>0$, $b>0$, $c>0$ and $a+b+c=1$, prove that: $$\frac{a^3}{a^2+b^2}+\frac{b^3}{b^2+c^2}+\frac{c^3}{c^2+a^2}\geq \frac{1}{2}$$


Geting a data plan in Japan as a tourist

I will be visiting Japan for two weeks as a tourist. I would like to have Internet access on my phone at all times, and found that there are some mobile data options for tourists. How do they actually work? Especifically:  Can I bring my european phone, put the sim card in and it works or will I need to rent/buy a japanese terminal? How is the signal through Japan? Will it work only in big cities, on most populated areas or all through Japan? Where can I buy them?  What is the cost and the data cap like? What is the process of geting one? Will I need to sign a contract, show them my ID and all that or can i just pay and get the card inmediatly?  This is all both to be able to make a decision beforehand if it is indeed worthwile and to make sure I dont get scammed once I get there.


Achievements indicator no longer showing number for rep change

In the last hour or two I've gotten green notifications for rep changes, but they look like badge notifications because there's no number:    I sometimes see this graphic appear for something less than a second and then be replaced (or overlaid?) by the number, but this stayed the same over time (a few minutes in the header, and I left the drop-down in the screen shot in place for several seconds).  This has happened a few times.  (OS 10.6, Firefox 31.0 and Chrome 36.0.1985.125, no known recent changes in add-ons.)  Edit: I just got a number-bearing notification on my Android phone (Chrome), but this bug is still showing in Firefox on my Mac.


Connect two monitors on macbook pro 2018 by using single docking station

I am going to buy a Macbook Pro 2018 15". I am just wondering, if it is possible to connect two monitors via one docking station. If there is any docking station, which it supports 2 monitor connections and extending the view (not mirroring). I don't want to use 2 hdmi adapters because I will need to buy the docking station anyway to have usb and ethernet connections.


Download directory structure explanation - Ubuntu

When downloading Ubuntu(Desktop version), for example Ubuntu 16.10 (Yakkety Yak) Netboot. After choosing arhitecture for example (i386) download directory opens and there is list of files:  Index of /ubuntu/dists/yakkety-updates/main/installer-i386/current/images/netboot  boot.img.gz ldlinux.c32 mini.iso netboot.tar.gz pxelinux.0 pxelinux.cfg/ ubuntu-installer/ xen/  Where can I find explanation what is the meaning of those files ad which one is correct for me ?


I have seen a few solutions but I can't apply them to this particular question. The question is:   Prove that $\cot 142.5° = \sqrt{2} + \sqrt{3} - 2 -  \sqrt{6}$  Help would be really appreciated.


I'm working in a framework written by another developer and I'm only allowed to touch the scss(css) but not the html. I am writing in scss and I need to change the style of an h1 inside of a div with the class "13_steps". But I can't get my style to take effect.   Example html:

Headline

   Example scss:  .13_steps {    h1 {      color: black;    } }   I have a vague recollection of once reading that you should not name selectors "[some number]_[name]"... but I can't remember why or even if that is my problem. Does anyone have any info or ideas?


Sorry if this problem is repeated.  Is there a nonempty perfect set in $\mathbb{R}^1$ which contains no rational number?  Proof sketch: This set must be uncountable because any nonempty perfect set in $\mathbb{R}^k$ is uncountable.   We know that Cantor set (C) is perfect set on a line. If we take $E=C+\sqrt{2}=\{x+\sqrt{2}: x\in C\}$. Will this set be an answer to above problem?


Why were the TIE Fighters shooting at BB-8 on Jakku?

Luke Skywalker has vanished. In his absence,              the sinister FIRST ORDER has risen from the              ashes of the Empire and will not rest until              Skywalker, the last Jedi, has been destroyed.              With the support of the REPUBLIC, General              Leia Organa leads a brave RESISTANCE. She is              desperate to find her brother Luke and gain              his help in restoring peace and justice to              the galaxy.              Leia has sent her most daring pilot on a secret              mission to Jakku, where an old ally has              discovered a clue to Luke's whereabouts....   If the First Order's plan is to search out and destroy Luke Skywalker, why do they order TIE Fighters to shoot at the BB unit which contains their only means of finding him? Doesn't shooting at the droid containing invaluable data defy all logic and directly contradict the entire plan?  If someone kidnaps the President of the United States and speeds away with him, the secret service wouldn't call for an Apache attack helicopter to blow up the vehicle containing the President, would they?  This is similar to the asteroid chase scene in The Empire Strikes Back when the Star Destroyers were shooting at the Millenium Falcon even though Darth Vader wanted Han Solo alive, but I have theorized that the Star Destroyers were actually ordered to shoot at the engine in order to disable the Falcon (but Han just thought they were out to kill them). The same can NOT be said for the TIE fighters shooting at BB-8 in The Force Awakens, though (for obvious reasons).  Any ideas?


If $U$ is unitary operator then spectrum $\sigma(U)$ is contained inside the unit circle

In a Hilbert space, let $U$ be a continuous operator which it unitary. Prove $\sigma (U)\subseteq \Bbb{S}^1$.   It is important for me to know how I am doing, and I didn't come by a clear explanation so it would be appreciated to have your correcting and guiding.  Attempt: $U^{*}U=UU^{*}=I$ and therefore $U^{-1}=U$. I have $$ \| U x \|^2 = \langle U x, U x \rangle = \langle U^* U x, x \rangle = \langle x, x \rangle = \|x\|^2 $$ and the same goes for $U^*$ and therefore $\| U \| = \| U^{-1} \| = 1$.   Looking at $U-\lambda$ I can take $$ -\lambda U(U^{-1}-{1\over \lambda}I) =U-\lambda I. $$ Clearly, for $\lambda \ne 0$, $-\lambda U$ is defined and is a linear operator. $(U^{-1}-{1\over \lambda}I)$ is invertible if $|\lambda|\ge 1$ and therefore $\sigma (A^{-1})=\sigma (A)\subseteq \{|z|\le1\}$. But from the RHS, $U-\lambda I$ is invertible if $|\lambda|\le 1$ and therefore $\sigma(A)\subseteq \Bbb{S}^1$. I have noticed my claims tend to have holes in them many times which I cannot spot. If it is substantially true, how can I make sure it is completely formal?


I'm working on a text editor in pure Javascript. I'd like it so that when the user clicks the 'Save' button, the editor downloads the file. I've already got this partly working:  uriContent = "data:application/octet-stream," + encodeURIComponent(codeMirror.getValue()); newWindow=window.open(uriContent, 'filename.txt');   The file downloads, but the problem is that the file is named 'download'.   Question: How could I change the name of the file to be anything I want, e.g filename.txt?


Nullpointerexception detected with AsyncTask

I am developing an app that downloads an XML file, parses it and then displays the information on the screen.  I get a NullPointerException Exception error in the following code:  here is the code:  private class DownloadXmlTask extends AsyncTask<String, Void, List<vehicleInfo>> {     @Override     protected List<vehicleInfo> doInBackground(String... url) {         try {             return getvehicles.processBusTime();         } catch (IOException e) {            return null;         } catch (XmlPullParserException e) {             return null;         }     }      @Override     protected void onPostExecute(List<vehicleInfo> result) {               for (int record = 0; record < result.size(); record++) {              double latitude = result.get(record).latitude;             double longitude = result.get(record).longitude;                  mMap.addMarker(new MarkerOptions().position(new LatLng(latitude,     longitude)).title("Marker"));          }      } }   it is returns a NullPointerException at the line:  for (int record = 0; record < result.size(); record++) {  what could be the issue?  thanks.


Windows 7 taskbar: How to uncombine only some icons?

For most applications, like Explorer Windows, Browsers, etc. the default automatic grouping of Taskbar buttons is really appropriate, avoids opening unnecessary additional windows, and keeps everything much more organized.  However, since I installed Windows 7, I've been annoyed by the fact that there are some applications which would benefit by staying ungrouped, even if the rest of the applications continue to follow the default "Always Combine" behavior.  For example, with this automatic grouping behavior, all Windows Live Messenger chat windows are also grouped (of course), but that means you have to click TWO times EVERY TIME you want to get to one specific chat window. (or similarly, to wait till the taskbar preview comes up and then click). Additionally, the taskbar button of lights up whenever there's a new message/feedback from any of the chat windows, but there´s no way to quickly know from which one of the open chat windows is this feedback coming.  It would be great to keep them separated, so that each has its own Taskbar button, while the rest of the Taskbar buttons would stay grouped.  Is there any way to do this ?  PS: Took this text from  since it perfectly describes what I am trying to do.


MTG - Priority and timing between instants and instants -

Well, , what happens if I have priority and cast an instant that gives +1/+1 to that creature, and then, giving priority to the opponent, he/she casts  in order to kill the creature counting on that it resolves before my instant (giving +1/+1 to the 2/3 creature)?  In other words, here's the order of the spells:   Summoning of a 2/3 creature Priority is mine, and I cast an instant (giving +1/+1 to the 2/3 creature just summoned) I give priority to my opponent, and he casts a lightning bolt with the 2/3 creature as a target.   What happens? Does the Lightning Bolt kill the creature, or not? The stack is now:   Lightning Bolt on the top My +1/+1 instant on the bottom


19.04 Unable to correct problems, you have held broken packages

I have Kubuntu 19.04 installed on a home server and unfortunately I never upgraded it. I am getting "Unable to correct problems, you have held broken packages" when I try to install packages like soundkonverter. I have tried doing a release upgrade but upgrading from disco to focal is not supported. What can I do to get on 20.04?


I have problem with referring tables in Latex. The output is always in form of "??" (see screeshot please). However, I got no problem with referring figures.     is illustrated in Table \ref{table:a}:   \begin{table}[h] \begin{center} \begin{tabular}{|>{\centering\arraybackslash}m{0.7in} | >{\centering\arraybackslash}m{0.6in} | >{\centering\arraybackslash}m{1in}| >{\centering\arraybackslash}m{1in} | >{\centering\arraybackslash}m{1in} | >{\centering\arraybackslash}m{1.2in} |} \hline ... \hline \end{tabular} \label{table:a} \caption{Remote sensing image scene classification approaches} \end{center} \end{table}   Screenshot:


I'm using the \author and \title commands to produce a title with \maketitle. I also know that there is a \date command to specify the date of my work. However, if I omit \date, \maketitle will produce the current date. How do I achieve that no date is displayed at all?  \documentclass{article}  \author{Author, A.} \title{Alpha}  \begin{document}  \maketitle  Some text.  \end{document}


Proving the sum of the reciprocals squared converges

I'm investigating the Basel Problem, and the sum to consider is:  $\dfrac{1}{1^2}+\dfrac{1}{2^2}+...+\dfrac{1}{n^2}$  How can I show this converges? Using graphs/computer software is also fine, but how would I do it? Is there a way using calculus?  I've looked on Google for a while and I found a few proofs, but I didn't understand any of them.


Does gravity slow the speed that light travels?  Can we actual measure the time it takes light from the sun to reach us?  Is that light delayed as it climbs out of the sun's gravity well?


Difference in length of study between Europe and the states?

It seems like in most European countries a student has to take a 3 years B.Sc, 2 years M.Sc and then 5 years phd program while in the U.S the M.Sc is skipped but the length of the phd stays the same...   (Specifically talking about CS, but may relate also to other fields)  Is that correct, and if so, why is that?


I am a complete JSP beginner.  I am trying to use a java.util.List in a JSP page.  What do I need to do to use classes other than ones in java.lang?


Non-linear Ordinary Differential Equation solution method

How would I obtain the following solution to the following non-linear ordinary differential equation:  $$ \frac{1}{2}\left(\frac{dR}{dt}\right)^{2}-\frac{GM}{R}=E $$  Where $E<1$. The solution has the form:  $$ R(\theta)=R_{0}(1-\cos\theta) $$ $$ t(\theta)=t_{0}(\theta-\sin\theta) $$  It is an equation which crops up in cosmology and galaxy formation, in terms of spherical collapse. But often, this solution is just given. No actual method for arriving at this solution.


Can I use a Verizon iPad mini with Wi-Fi only?

A friend just gave me his Verizon LTW iPad mini. I don't have Verizon.  Do I need to remove the SIM card to use it on Wi-Fi only? What problems will I encounter not having Verizon and trying to use this device? What settings do I need to turn off to disable Verizon's service on this device? How does this SIM card get removed?


Did the Others come back with the magic?

In the series, we see magic starts to come back with the birth of the dragons. We also see a resurgence of the Others as the series moves on.   Is there any correlation between these two events? Are the Others mystical creatures that exist only when magic does or have they just been amassing their strength until now?


Started learning c but don't know why we are using Return 0

I started studying c programing.while learning some basic programs I got a doubt that why we r using "return 0" at the end of the program even if I am not writing that return 0 also I am getting correct outputs ( for basic programs). I want to know... 1) what is the need of using? 2)if we won't write what will happend?


Character Accent Menu doesn't appear anymore in macOS Sierra

Before upgrading to macOS Sierra, I really liked the Character Accent Menu by doing a long press on a key (for example, the character e) and being able to add an accent on it.   However, this functionality seems to not work anymore, and so far, I can't find out why?   Also, before, doing a long press on the delete button, would repeatly delete characters. Now, it is doing only one character deletion disregarding how long I'm pressing the key. So if I want to erase 10 characters, I need to press the delete button 10 times...  Also, I am not able to log off or shut down. When doing it, all applications are closed, status bar disappears but nothing happens. The dock remains here. I have no way to shut down or log out without doing a long press on the power button.  Is someone facing the same issue?  EDIT : Logging with a new user account or guest account fix all the problems. But I still would like to know what, in my user account, became corrupted during the upgrade.


Help finding a sci-fi book with a small space ship

It's a book I read probably sometime between 2003-2007 but it may have been published much earlier, I have a vague feeling it was from the 1990s. I'm in the UK. Stuff that I remember (sorry it's so vague!):  I think the cover was dark blue with stars on. It's quite a long book. It's sort of a mystery. It's set on a non-Earth colony world and FTL travel is fairly commonplace There's a female protagonist One of the other characters has (I think) a business which does space exploration On his desk he has model space ships, but one of them is an actual alien spaceship with small dead aliens inside There are stories about ghosts haunting something, I think it's underwater or on a beach. The ghost turns out to be an alien AI which was supposed to protect the little craft but has escaped somehow. They went on an exploration mission in the past which went badly and that's how they came back with the tiny ship The stars Alnitak and Alnilam are involved - I think that's where they picked it up The protagonist steals(?) a spaceship and goes back to where the others originally found the ship to solve the mystery.  I tried searching around for Alnitak and Alnilam but because they're just real star names I haven't had much luck.


Flagging a deleted answer results in a message saying I am flagging too quickly

Steps to reproduce:   Open two questions (with answers, in this case) in different tabs in the same browser Flag an answer to one (might not be needed, but it's what I did, so I'm including it) Someone else (might need a diamond for this) deletes an answer to the other Without reloading the second tab, try opening the flag dialog on the now deleted answer   Environment: Firefox 46.0.1 on up-to-date Windows 8.1.  Actual result: The UI responds with a message stating that I am opening the flag dialog too quickly.  Expected behavior: (A) The flag dialog should open, as happens after I reload the page and click "flag" again. Alternatively, (B) a message should be displayed saying that the answer is ineligible for flagging. If the user doesn't have the reputation necessary to see deleted posts, always do (B).  Something like this, shamelessly borrowed from :


I'm looking at removing password-based logins for SSH.  However, I don't want to allow passwordless ssh keys, as that would be even worse.  How can I make sure that only SSH keys which have passwords can connect?  If this can't be done, are there alternatives, like centrally managing SSH key generation, and preventing users from generating and/or using their own keys?  Something like PKI, I suppose.


Why are effect size estimates (such as $R^2$) difficult in mixed-effects models?

I have been reading a lot online about estimating standardised effect sizes in mixed effects models and it seems like there are formidable challenges even for something relatively broad like an $R^2$, let alone for contrasts. What is a simple explanation (that I could supply to a reviewer) for why effects sizes are so challenging to perform in these more complex models?


How to get Gnome 3.14 on UbuntuGnome 14.04LTS

I just read that GNOME has been updated to version 3.14 () and I was wondering if there was a way to update the current release of UbuntuGnome 14.04.1 LTS to that new version of GNOME?


What this strange output in Network Utility means when I do whois for apple.com?

I did a whois command for apple.com in Network Utility and got output which incluces this text:    APPLE.COM-INTERNATIONALSECURE.COM APPLE.COM.AT.WWW.BEYONDWHOIS.COM APPLE.COM.BEYONDWHOIS.COM APPLE.COM.HACKED.BY.JAPTRON.ES APPLE.COM.IS.0WN3D.BY.GULLI.COM APPLE.COM.IS.OWN3D.BY.NAKEDJER.COM APPLE.COM.MORE.INFO.AT.WWW.BEYONDWHOIS.COM APPLE.COM.WAS.PWNED.BY.M1CROSOFT.COM APPLE.COM.WWW.BEYONDWHOIS.COM APPLE.COM.WWW.ZON.COM APPLE.COM.ZON.COM APPLE.COM   I got this output both when I was at home and at work. What this could mean? When I do whois for apple.com on thirdparty services in browswer, I do not get this output. Is something wrong with my system? (10.12.2, MBP Late 2013.)