Posted by sarah on Tuesday, February 26, 2008 at 11:10pm.
determine whether the series converges of diverges
the sum from k=1 to infinity of
cos(e^k)
I'm not sure where to start..

calculus  drwls, Wednesday, February 27, 2008 at 12:42am
As k becomes very large, e^k approaches zero, and every cos(e^k) term approaches 1.
You end up with an infinite series of terms all approaching +1, which cannot converge