1. ## Infinite Series

lim cos[pie]n/2
n-[inf]

does converges? If it does what is the limit?

2. Originally Posted by homerb
lim cos[pie]n/2
n-[inf]

does converges? If it does what is the limit?
Are you doing $\lim_{n\to\infty}\cos\frac{\pi n}2?$

What is the cosine of a multiple of $\frac\pi2?$ Look at the unit circle: if $n$ is odd, you get 0, and for even $n$ the value alternates between 1 and -1.

Is the sequence approaching a single finite value?

3. Yes it goes to infinite

4. Originally Posted by homerb
Yes it goes to infinite
Huh? I said finite value. And anyway, would you mind explaining how the cosine function, which has a range of $[-1,1],$ can reach infinity?