I was looking for some explanation in the FAQs about this problem but I could not find anything.  I will explain:   User A asks a question about X User B starts helping him in the comments. After a few comments, User A asks User B to talk with him by email (giving his email in a comment) User B answers yes and posts his email too.   I want to discuss two things:   First, is it legal to try to solve questions where at first you use Stack Overflow as platform to get solved and then you solve with another Stack Overflow user by themselves without letting us know what happens? Second, why would these people resort to this method instead of using Stack Overflow like all of us?
I've come across quite a few answers that request the asker to, for example: "send the user an email", after which the answerer will provide them with the code or other resources they're looking for.  A few examples:          Should we take action against these questions?  I feel like these answers aren't appropriate (see my answer below).  Update:  Perhaps there are some cases where this is acceptable. I've seen a few questions regarding a particular piece of commercial software where the author/developer of the software answers, telling the asker to contact either them or their organization's in-house support.  I'm on the fence about this case. If I came across a question here describing a similar problem I was having, it would be useful to me to have the support information and know that I could contact it for assistance.  I'm interested in others' opinions on this situation in particular.
How to Update Multiple Array Elements in mongodb Enclosing Page Numbers using the `Backref=Pages` Extension of `Hyperref` Quick question about curly braces not showing up Ii am writing a short code, so I doubt anything else in the code is causing the problem. This is the problematic line of code:  \[ M_R := \max {|f(z)|: |z - z_0| = R }\le M\]   It doesn't show the curly braces. I've tried using \left{ and \right} but to no avail.  What should I do?  Thank you Algebraic dual of $\mathbb{R}^{\mathbb{N}}$ As in the title, my question is: What is the algebraic dual space of $\mathbb{R}^{\mathbb{N}}$ - the space of all $\mathbb{R}$-valued sequences. I think that it should be the direct sum $\bigoplus_{\mathbb{N}} \mathbb{R}$, via the natural duality, but I cannot proof it. Intermediate ring between a field and an algebraic extension. This is an exercise in some textbooks.     Let $E$ be an algebraic extension of $F$. Suppose $R$ is ring that contains $F$ and is contained in $E$. Prove that $R$ is a field.   The trouble is really with the inverse of $r$, where $r\in R$. How to prove that $r^{-1}\in R$, in apparent lack of a characterization of $R$.  It occurred to me to use the smallest field containing $R$ ($R$ is easily shown to be an integral domain), that's the field of quotients, and proving that it's $R$ itself, but I don't really know how to proceed.  A not-too-weak, not-too-strong hint will be much appreciated.   Beware $ $ Readers seeking only hints should  beware that there is now a complete answer. Let $f$ and $g$ be entire functions such that $f^n+g^n=1$, where $n\geq 3$ is an integer. Prove that $f$ and $g$ are constant.  I suppose I should somehow prove that either $f$ or $g$ is bounded so that I can apply Liouville's Theorem, but I don't see how. I tried setting the derivative of the left hand side equal to zero and work with that but that did not seem to work. By viewing the polynomials as a difference of two squares, factorise the following polynomial: $$x^4+x^2+1.$$ I searched but couldn't find a way to solve this  Edit: By using Hans Lundmark hint, I get:  $$(x^2+1)^2-x^2$$   Is it fully factorized? Discrete mathematics - Find all integer solutions of the equation $a^2+ b^2 + c^2=a^2 b^2$. Find all integer solutions of the equation $a^2+ b^2 + c^2=a^2 b^2$.  This is one of the questions we presented in one session to contest preparation PUTNAM. It turns out that I can't get from the problem. Could someone just give me a hint? (Please, don't give me the answer. Simply, an argument that can help me advance in the problem or theorem might suffice.) Say we have the following sample and we are trying to estimate the variance of the sample mean of the population.  X = [0, -1, 2, 10, -3]   If I take an increasing number of bootstrap (e.g. 100, 1000, 10,000, 100,0000), the bootstrap distribution of the sample mean gets narrower and narrower. In other words, I can make the bootstrap distribution arbitrarily narrow.   Given the above, what's the point of using a different number of bootstrap samples here? And wouldn't this mean that I could make the standard error of the mean arbitrarily small by just taking more and more bootstrap samples? What am I missing?  Please note that I am doing a proper bootstrap sample in the sense that each bootstrap sample has the same exact size as the original sample (input array). How can I disable the “News and Interests” Widget on the Windows 10 Taskbar? On Windows 10 version 1909 and newer releases, Microsoft has added a &quot;News and Interests&quot; widget on the Taskbar (see ):  How can I remove this Widget from the Taskbar? What is the difference between would and will in the following examples?        How would you use this word in a sentence?     How will you use this word in a sentence? How can I search the bash history and rerun a command? Can I search history in bash and run the result? I miss those pins I make in Windows.     How can I do the same in Ubuntu 17.10 with GNOME 3? I've a file named addresses.txt :  address1@domain.com address2@domain.com address3@domain.com   I'd like to echo "address1@domain.com.html" using for loop. Here's what I did :  cat addresses.txt | while read address do echo "${address}.html" done   Here's the result :  .htmlss1@domain.com .htmlss2@domain.com .htmlss3@domain.com   Same result if I add a space between the variable and ".html"  What am I miss ?  Thanks Achievements tab isn't working in Area 51 When I try to bring down the Achievements tab in Area 51, it's showing an error dialogue.  Strangely enough, the global inbox dropdown works just fine.  Could be connected to .  Screenshot: Is JavaScript's "new" keyword considered harmful? In another , a user pointed out that the new keyword was dangerous to use and proposed a solution to object creation that did not use new. I didn't believe that was true, mostly because I've used Prototype, Scriptaculous and other excellent JavaScript libraries, and everyone of them used the new keyword.  In spite of that, yesterday I was watching Douglas Crockford's talk at YUI theater and he said the exactly same thing, that he didn't use the new keyword anymore in his code ().  Is it 'bad' to use the new keyword? What are the advantages and disadvantages of using it? Is the graviton hypothetical? Wikipedia lists the  as a hypothetical particle. I wonder whether graviton is indeed hypothetical or does its existence directly follow from modern physics? Does observation of gravitational waves amount to the discovery of graviton or could there be gravitational waves not composed of gravitons? Feed can show entries for deleted posts, which viewing them fails Just noticed this:  Someone @replied to me in a question which appropriately showed up in my feed.  I go to click on that notice in the feed, and it presents me with "Loading the question failed."  I'd show a picture, but I don't think that it's entirely relevant - I believe it's reproducible if an answer is posted, someone makes a reply, the answer is removed, then that someone else goes back in the feed to try and revisit the post.  Alternatively, why not synchronize the interface between what a 10K user sees on the site, and what they see in the app?  As a 10K user, I would expect to see deleted questions and answers. How to change symbol for footnote in minipage \renewcommand method does not work  \documentclass{article} \renewcommand{\thefootnote}{\arabic{footnote}} \begin{document}  \begin{minipage}{1.3\textwidth}  test this\footnote{abc} \end{minipage}  \end{document}   In the following example the footnote number is incorrect. Why?  \documentclass{article} \renewcommand{\thempfootnote}{\arabic{mpfootnote}} \begin{document} \begin{minipage}{.5\textwidth} test this\footnotemark \footnotetext{abc} \end{minipage} \end{document} How to show  that $\mathbb{Z}[i]/I$ is a finite field whenever $I$ is a prime ideal? Is it possible to find the cardinality of $\mathbb{Z}[i]/I$ as well?  I know how to show that it is an integral domain, because that follows very quickly.