TrigIdentity Intermediate

Problem - 3154
Evaluate $\cos\frac{2\pi}{2n+1}+\cos\frac{4\pi}{2n+1}+\cdots+\cos\frac{2n\pi}{2n+1}$.

The solution for this problem is available for $0.99. You can also purchase a pass for all available solutions for $99.

report an error