May i know (cos n pi ) with n to infinity is converges or diverges?

1. Feb 16, 2006

teng125

may i know (cos n pi ) with n to infinity is converges or diverges??

may i know (cos n pi ) with n to infinity is converges or diverges??

2. Feb 16, 2006

quasar987

Use the fact that if a sequence converges, the limit is unique, and the fact that if a sequence converges towards x, all subsequences converge towards x also.

Can you find 2 subsequences of {cos npi} that converges towards different numbers?

3. Feb 16, 2006

teng125

is it -1 and +1 ??

4. Feb 16, 2006

quasar987

Is there a doubt in your mind?

5. Feb 16, 2006

teng125

yaya.pls explain to me

6. Feb 16, 2006

quasar987

Is this in the context of an analysis class?

Are you familiar with the two theorems I quoted in my first post?

7. Feb 16, 2006

teng125

no,what is subsequence??

8. Feb 16, 2006