12:44 AM

7 hours later…
7:55 AM
Request for closure and/or deletion: https://math.stackexchange.com/questions/4215564/find-lim-x-to0-left-lim-n-to-infty22n-left1-leftf-circ-nx-ri

Very low-quality post. The problem is a classic one: the $x=\cos(\theta)$ sub is the simplest approach exploiting the cosine double-angle formula leading to $\pi^2/16$, yet OP refuses to elaborate and instead "ask for other approaches as it will be helpful to them and others of the community."

I'm amazed the only close vote on it is mine till now (though, with 3 downvotes already).

3 hours later…
11:06 AM
One more vote needed: C1
For closure: C2, C3, C4, C5, C6,
C7, C8, C9, C10, C11, C12
For deletion: D1, D2, D3, D4, D5, D6
@Peter I'm not 100% sure, and still waiting for mods to deal with my pending flags.

11:25 AM
@PrasunBiswas It's been self-deleted, the approach via the cosine substitution was available in an answer I found just yesterday, maybe the question was by the same author.

1 hour later…
12:51 PM

1:43 PM
The answer given in the supposed duplicate uses the class equation. Here is the question.

1 hour later…
2:43 PM

3:40 PM
This trivial answer has a trivial error.

4:03 PM

4:33 PM
This is a repost by the same user (I’m pretty sure it’s the same content, it’s definitely the same user): math.stackexchange.com/q/4215878/29335 I used to be able to get back to deleted questions via the RSS feed but since I’ve neglected to replace my broken reader I haven’t had that option. Are there other ways of finding recently deleted things without having bookmarked them?

5:15 PM
@TheSimpliFire Some times users post single observations here, @TheSimpliFire. whether humorous, or casual. Now: Scroll as far back as you'd like: when I post suggesting an action, I explicitly say so. Lighten up a bit.

5:59 PM
@TeresaLisbon Hmm, that might be the case. I knew the problem back from years ago on a math forum where I solved it, though it was formulated with $a_{n+1}:=\sqrt{(1+a_n)/2}$ and a seed $0<a_0<1$ with the limit expression being $\cos(2^{n+1}\sqrt{(1-a_n)/2})$ so that the answer would be a simple $\cos(\theta_0)=a_0$

6:39 PM

7:23 PM
4 messages moved to ­Trash

8:16 PM
I notice that this question has received two downvotes and two close votes (missing context). It is a reference request, so I'm not sure what other context those users were hoping for. Any suggestions as to how this question could have more context?