How to determine if $\sum_{n = 1}^{\infty}e^{(\pi*n*i)/2}*\frac{1}{n^2}$ is convergent

35 Views Asked by At

I am having trouble with determining if

$\sum_{n = 1}^{\infty}e^{(\pi*n*i)/2}*\frac{1}{n^2}$

is convergent. I don't know what will happen with $e^{(\pi*n*I)/2}$ when n approaches infinity. I am hoping someone can help! Thanks in advance.

1

There are 1 best solutions below

1
On BEST ANSWER

$\mid e^{\pi ni/2}\mid=1$, so by the comparison test with $\sum_n\dfrac1{n^2}$, it converges absolutely.