# Talk:4 Sine Pi over 10 by Cosine Pi over 5

I mentioned in the revision history that it is original work and based off of another proof of a different statement that I had written prior. That was a proof that $\cos \dfrac \pi 5 = \dfrac { 1 + \sqrt 5 } 4$; remnants of that old (unpublished and trivial) proof are still visible in this one, in the form of $\dfrac { 1 + \sqrt 5 } 4$ seen in the final section.
Don't worry too much about timestamps. Just click on the "Your signature with timestamp" button at the top of the edit pane (it looks like a squiggle). This puts --~~~~ on the page at the position of the cursor, which is then translated into the timestamp automatically when you save the page. No need either to generate it or to edit it by hand. --prime mover (talk) 05:04, 3 October 2018 (EDT)