# Asking competitive exam questions (to which I have solutions)

I have several books of standard exercises that were asked in competitive exams in France (typically, ENS/Polytechnique), from my earlier years.

In particular, a lot of them are quite interesting, either due to the techniques used or the ideas necessary to solve them. (They mostly are about sequences, series, limits, asymptotics.) In that sense, having them on Math.SE would be (I feel) a nice thing for students who want to self-study and practice.

While it seems unethical to just copy-paste them along with the solution (in CW), as the authors of the books did come up with solutions themselves, I am wondering if it is within the scope of the website to ask the questions, wait for answers (in order to have several approaches, hopefully), and eventually maybe provide my own solution (not verbatim from the books).

Note that while the answers are due to the books' authors, the questions themselves are not -- they are from previous exams, and were generally reported by the students who had to solve them.

• I've asked a large amount of such questions, although there were solutions already available either in books (from the Cassini collection essentially) or from the Revue de la Filière Mathématiques. Contributors in here often come up with different solutions, I think it's rather positive. Jan 13, 2017 at 7:37
• Fantastic! I'll start, then. Jan 13, 2017 at 20:22
• I see nothing against it. Obviously cite that the question is a past exam question. However, if it is normal enough it would probably just be a good question regarding ___. It all depends on the subject. Definitely cite it if it isn't a trivial question to come up with (like what is the solution to y'' + 2y' + y = 0?). Jan 13, 2017 at 21:08
• @TheGreatDuck, is that a question on the site already? Jan 14, 2017 at 4:25
• @Wildcard idk. I'm just giving an example of a question that might not need citation as it's a textbook example of a linear diff. eq. and not hard to think of. Jan 14, 2017 at 5:03
• It's a pity that this question (which is really good) is not getting answers. Even though the OP has got his/her answer (through comments), I think the question should be answered by someone just for the sake of it. Jan 14, 2017 at 5:31
• For reference: here is the first post/attempt I made (if that looks alright, i plan on following that format). Jan 16, 2017 at 13:40