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

[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??

 

[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?

 

[teng125]

is it -1 and +1 ??

 

[quasar987]

Is there a doubt in your mind?

 

[teng125]

yaya.pls explain to me

 

[quasar987]

Is this in the context of an analysis class?

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

 

[teng125]

no,what is subsequence??

 

[arildno]

First answer my question, teng:
What is meant by a "limit"?

 

[quasar987]

I put this conversation in your hands arildno, I have to leave.