Chewin in the Chung

Show that cos(pi/7) - cos(2pi/7) + cos(3pi/7) = 1/2

Hmm. OK.

0.900968868 - 0.623489802 + 0.222520934 = 0.5

That was easy.

I was going to prove that there is no integer solution for x^3 + y^3 = z^3, but this blog is too small to contain the proof.