Originally Posted by

**endreoc** The series is $\displaystyle cosh(n)/n!$.

I attempted the ratio test with lim n→∞ of:

$\displaystyle \frac{\frac{\cosh(n+1)}{(n+1)!}}{\frac{\cosh(n)}{n !}}=\frac{\cosh(n+1)}{cosh(n)}(n+1)=\frac{e^(n+1)+ e^(-n-1)}{e^(n)+e^(-n)}(n+1)$

and for me this means that L>1 if evaluated when lim n→∞, and so not convergent at all. However, the problem clearly states to determine whether the series converges absolutely or conditionally - hence why my conclusion obviously has to be wrong, and I am making some sort of mistake. I hope you guys can help me see what I'm doing wrong here.

Thank you for your time!