It seems to me that I have misunderstood mathematica.stackexchange.com's purposes. I understood two purposes: to teach and to learn. It seems to be a place for ignorant newcomers to Mathematica to demonstrate their limited knowledge of Mathematica and their limited programming experience and for the mandarins to receive kowtows from such people on the basis of snide comments which if you already had most of answer might be just enough to bring the original questioner to enlightenment. If the issue is handled at all, then it usually is answered finally someone just a little more advanced than the original questioner whose has determined an answer.
Can/should we have additional reasons for closing? alludes to some of these issues:
..., the asker may be an absolute beginner who simply does not know where to begin or hasn't yet arrived at a coherent conceptual model of how Mathematica works.
Moreover, they are the kind of questions to which anyone with
anyconsiderable familiarity with Mathematica already knows the answer without even having to think about it, but where a new user may need a push in the right direction. A push in the correct direction is not a bare RTFM. It is providing instruction on which Fine Manual (page) to Read; if necessary, how to access that manual; and, possibly which line to read.
The practice given hints in comments is frustrating. Please, see How do you define the domain of a plot? “@mike The answer in your comment is correct, but in the future you'd better provide it as a formal answer in the answer box and preferably with a bit of explanation. – Sjoerd C. de Vries Feb 24, 2012 at 13:00”