- #1

MaximumTaco

- 45

- 0

\sum_{n=1}^\infty \frac{cos n}{n^2}

[/tex]

Now, which test should i try? It doesn't appear to be anything straightforward like ratio test, comparison test etc and it's not a straightforward limit.

cos(n) goes negative too, so that complicates things.

Can anyone offer me any advice on a problem like this? Thanks!