Sometimes this "What have you tried" thing seems silly.
Take this question [edit: question deleted/link broken] for example. It's obvious that one should try to do it by induction, but it's not the same as asking how to prove $\sum_1^n j=n(n+1)/2$, in that it's not obvious, or at least it wasn't obvious to me, how to make the proof by induction work.
Supposing that's so, what would "I tried to do it by induction but I don't see how" have added? I gather that that would make the question more acceptable, but I really don't get it.
Edit: I've been told that's a senseless question because the answer is obviously "that would have added nothing". It was a rhetorical question, sorry.
Next question: Fine. Then what specifically could the OP have said, about that question, regarding what he'd tried, in order to show he'd worked on it?
That's rhetorical as well, although much less so, certainly less obviously so. I can't imagine anything specific the OP could have said along those lines. Here's why: I did spend a few minutes "working" on the question. Wasn't going to give it a lot of time, but I did work on it, cuz it pissed me off, seemed like something I should be able to do. But during the time I was working on it it didn't happen once that I tried something that failed. It just wasn't that sort of difficulty - where I was stuck was thinking of something to try.
It's a fact that I did work on it, and it's a fact that if I hadn't seen the solution I'd be totally unable to give any evidence whatever that I'd worked on it.
My point, for those to whom it's not clear, carefully phrased as a question: Might it not be a good thing if before whining about "show your work" we stopped to consider that there is such a thing as working on a question without being able to produce evidence to that effect?
Supposing one agreed with that in principle, one could try to avoid asking unreasonable "what have you tried?" questions by making certain that before asking that one actually had at least a reasonable approach in mind. (In the question I'm talking about the guy who said "Try induction" more or less admitted when asked that he didn't see how to do it by induction. Suggesting induction as something that might work, fine, bbut suggesting as though it was clear it was something the OP should have tried but didn't, not fine unless we do see how it works.)
(So as to avoid answering questions from someone who really has no clue and hasn't even considered induction, I posted an answer which it seems to me should help only if the OP is thinking about induction...)