$\displaystyle \sum_{k\ =\ 0}^n (cos 1)^k$

i'm supposed to tell if this converges or diverges, & if it converges, evaluate the sum

i know that cosine oscillates..but because it's cosine of a specific value, i'm a little confused. since cos 1 is about 1, will this just go up to infinity? and if so, how would i show it?