Find the interval of convergence for ∑n=1∞(−1)nxnn2\sum_{n=1}^{\infty} \frac{(-1)^n x^n}{n^2}∑n=1∞n2(−1)nxn.
(−1,1)(-1, 1)(−1,1)
[−1,1][-1, 1][−1,1]
(−1,1](-1, 1](−1,1]
[−1,1)[-1, 1)[−1,1)