# Math Help - convergent-divergent question

1. ## convergent-divergent question

here is the problem:
an = cos(2/n^2)
Do I divide top and bottom by n^2 to get cos(0) = 1 ?
then it converges but I don't feel confident because I am not sure how to do this one, there is no example in the book to compare to.
Thank you,
Keith

2. Originally Posted by keith
an = cos(2/n^2)
Do I divide top and bottom by n^2 to get cos(0) = 1 ?
Do you know that $\frac{2}{{n^2 }} \to 0$?
If so, then you know that cos(0)=1.
That is simply all there is to it.

3. Just remember what Plato did works here because cosine is a continous function.

4. Originally Posted by Plato
Do you know that $\frac{2}{{n^2 }} \to 0$?
If so, then you know that cos(0)=1.
That is simply all there is to it.

Thank you, it just seemed too simple an answer, I just thought it was wrong.