$\sum _{n=1}^{\infty }\dfrac {\sin ^{2}3n } {n\sqrt {n}}$
İpucu:
$$\frac{\sin ^2 3n}{n^{\frac32}}\leq \frac{1}{n^{\frac32}}$$ ve $$\sum_{n=0}^{\infty}\frac{1}{n^{\frac32}}$$ serisi yakınsak.