$\begin{align}
&S_1=\displaystyle\sum\limits_{n=1}^{\infty }{\frac{{{\left( -1 \right)}^{n}}}{n^2}}
\\\\
&S_2=\displaystyle\sum\limits_{n=1}^{\infty }{\frac{1}{n^2}}
\end{align}$
**Which series converges?**
[[☃ radio 1]]
**Based on your answer, what can we say about $S_1$?**
[[☃ radio 2]]