# Can we ask question by referring the equations, say, in an article in Wikipedia?

I was reading about "Poisson summation formula" in Wikipedia, yet there is something I can't understand. So can I copy the link and say I did not understand this and this in that link?

It seems wrong because I don't remember seeing such questions but if it is ok, easier.

• If you google a bit, you will find several questions asking for clarification of some Wikipedia article. Examples: Understanding isPrime function from Wikipedia, Explanation of derivation made at wikipedia. or Is the Wikipedia article on the proof for Bertrand's Postulate correct? Commented Dec 23, 2015 at 16:37
• I asked to me this kind of questions (for example, if I plot a graph of a function using a widget of Wolfram Alpha, can I do a copy paste in this site, in a post, of the image, is it right?). I don't know neither I don't ask your answer, I hope that the answers of the users can clarify to you.
– user243301
Commented Jan 2, 2016 at 10:46
• I don't see why not. Reading Wikipedia can cause confusion in the first place, though. Just saying. Commented Jan 4, 2016 at 22:32

• Usually,1 it should be relatively easy to copy a formula from Wikipedia. This might browser-dependent, but probably already selecting the formula and trying to copy-paste will give you a format suitable to use here. But what should work reliably is viewing the source (by clicking on edit), finding the formula there and copying it. For example, in the article you mentioned you can find this: \sum_{n=-\infty}^\infty f(n)=\sum_{k=-\infty}^\infty \hat f\left(k\right). Exactly the same syntax works here: $$\sum_{n=-\infty}^\infty f(n)=\sum_{k=-\infty}^\infty \hat f\left(k\right).$$
1For simple and inline formulas, you will often find some combination of HTML and Wikipedia syntax, like here: L<sup>1</sup>('''R'''). So this only works for formulas enclosed in $...$.