IMO PROBLEM 1963
-
- Posts:190
- Joined:Sat Apr 23, 2011 8:55 am
- Location:Khulna
Prove that,cos $\frac{\pi}{7}$-cos$\frac{2\pi}{7}$+cos$\frac{3\pi}{7}$=$\frac{1}{2}$.
Unread post by MATHPRITOM » Mon May 02, 2011 7:50 pm
Return to “International Mathematical Olympiad (IMO)”