# Test the convergence of the series Σ cos1/n from n=1 to ∞ | Test the convergence of the series Σ root(n/(n+1))

## 1. Test the convergence of the series \sum_{n=1}^{\infty}cos\frac{1}{n}

**2.Test the convergence of the series** \sum_{n=1}^{\infty}\sqrt{\frac{n}{n+1}}