Convergent Complex Series/Examples/((-1)^n + i cos n theta) over n^2/Proof 2

Proof
Thus $\ds \sum_{n \mathop = 1}^\infty \paren {\dfrac {\paren {-1}^n + i \cos n \theta} {n^2} }$ is absolutely convergent.

The result follows from Absolutely Convergent Series is Convergent: Complex Numbers.