Sometimes I see exactly the same question come up twice, and an example of this is shown below:        The questions shown might look different, but tapping on them brings me to exactly the same page, and on reporting one of the questions as a duplicate, I get this message:        Is this a glitch, or am I missing something? Please let me know.
The Stack Overflow search shows questions twice. See  for example.  Results include "A: Add Search Engine into MVC Music Store" and "Q: Add Search Engine into MVC Music Store".  Why is search displaying the question twice, and what does "Q" and "A" mean?  Edit:   @Stephen answer :  The search is returning both a question (Q) and an answer (A) to the question, as both posts match your search criteria.  and my another question  If the question have multiple (like 100) answer ,then the answer link(A: Question Link) shown 100 times?  Is it correct functionality ? But i saw only one answer link , not a other answer link .. why ?
Is it possible to save `bc` command line history? bash has a handy file .bash_history in which it saves the history of commands and on the next execution of bash the history is populated with saved commands. Is it possible to save bc command history to a file in the same way and then load it on startup so that bc history is preserved? I tried reading  and it mentions readline and libedit. From ldd /usr/bin/bc I see mine uses readline and readline has  and read_history functions. Is this functionality implemented in bc or to do it I'll need to patch bc? How do I open Chromium in incognito mode by default? I would like to be able to open Chromium in incognito mode automatically. I'm new to Linux and I love it so far but I haven't yet found a way to do this. I'm using Ubuntu 14.04. Why does the introduced part-title in letter appear twice? general solution sum of two uniform random variables aY+bX=Z? is there a general solution to that? I have seen simple examples for Y+X=Z but I was wondering how this would be with rescaling? Why wouldn't the `which` command work for `cd`? I can't find the executable for `cd` either! I tried which cd and it didn't give a path but instead returned the exit code 1 (checked with echo $?). The coreutil cd itself is working, so the executable should be there, right? I also ran a find for cd, but there was no executable file shown. How is it implemented then?  Update:  I don't know if I should ask this in another post but since I think it is good here, I'm expanding (?) the post... So the answer was actually quite simple, there's no executable for that — because it's a builtin — But I've found some builtins (bash shell in Fedora) have the executable files! So builtin -> no executable isn't right I suppose? Maybe an answer explaining what builtins actually are (builtin commands?), which actually is the matter here, rather than focusing more on cd... Some good links posted previously indicate that builtins are not programs... so what are they? How do they work? Are they just functions or threads of the shell? How to connect a Nokia Lumia 730 to Ubuntu 14.04? Why is it not possible to overload class templates? Realtek RTL8723BE Wi-Fi incredibly weak Iterating each character in a string using Python Obtaining consistent one-hot encoding of train / production data Minimal and characteristic polynomial have same set of irreducible factors Let $V$ be a vector space over a field $F$ (not necessarily algebraically closed), and $T:V\rightarrow W$ be a $F$-linear map. If $c(T)$ and $m(T)$ denote the characteristic and minimal polynomial respectively, then I want to show that $c(T)$ and $m(T)$ have the same set of irreducible factors.  I know that the claim is true if $F$ is algebraically closed, because then the two polynomials have the same roots. The typical reasoning one gives when $F$ is not algebraically closed is: Take an algebraic closure of $F$, say $K$, and look at $m(T)$ and $c(T)$ in $K$ to conclude the proof. But as far as I know, the proof that any root of $c(T)$ is a root of $m(T)$ requires the fact that $V$ is a $K$-vector space. But we only know that $V$ is an $F$-vector space. I can't understand how to proceed after this. Pipe sound output to file? When running 'screen ls' the screen stops with the text [screen is terminating]. I would like screen to keep the session alive and reattach to it to see the output of ls.  Of course the real thing is that I don't run screen ls, but rather a screen fsck ..., so I would like to ensure that the screen is not terminating when this command is finished.  I would love to have an answer that is useful for an already existing running screen session, so some interactive keys like C-a ... or C-a : (Enter command line mode) How to do vlookup and fill down (like in Excel) in R? Is it possible to query the content of the Time-based Workflow Queue from an Apex unit test to assess that a specific Workflow Rule has been executed and added a new item to the queue? I didn't see anything alike in the documentation, but wish it could be possible to improve testing and stability overtime.  Thanks How is effect precedence determined? I was using  and my opponent has a . I attacked Sylvanas, fearing that the Deathrattle will take control of one Hyena. I feel lucky, because it did not happen.  I want to know if there are some general rules of effect precedence.   Has Blizzard published something about this?  Are there articles teaching about precedence?   Please note, I want guidance about effect precedence in general, not just about Deathrattle. Is "of" instead of "have" correct? So I understand what a static method or field is, I am just wondering when to use them. That is, when writing code what design lends itself to using static methods and fields.   One common pattern is to use static methods as a static factory, but this could just as easily be done by overloading a constructor. Correct? For example:  var bmp = System.Drawing.Bitmap.LoadFromFile("Image01.jpg");   As for static fields, is creating singelton-objects their best use? Bounded operator that does not attain its norm What is a bounded operator on a Hilbert space that does not attain its norm? An example in $L^2$ or $l^2$ would be preferred.  All of the simple examples I have looked at (the identity operator, the shift operator) attain their respective norms. how to turbo boost my cpu on Ubuntu? My PC has one Intel Haswell i5 4690, which is supposed to be boosted up to 3.9GHz from the regular frequency 3.5GHz. I do not know if it is possible to use some softwares to turbo boost this cpu on Ubuntu 14.04LTS. THX!