> I
>can't think of any rules
>& test for limits that
>can find it. Can you
>help me, please?

I am sorry. I may only help you if you try helping yourself. Tell your teacher he/she sent you to a wrong guy.

You may try posting your question to the sci.math newsgroup. There's always somebody willing to solve somebody's homework. Do not know if you should call this help. Help is helping to study, not just supplying solutions.

If you still want me to help, then open your textbook, find limits that look like the general term of your series, make at least one step - try something. If you fail, I may be able to help you with the next step.