0

Finding Convergence or divergence of sequence $$a_{n}=\frac{2+(-1)^n}{n}$$

What I try :: A sequence $\{a_{n}\}$ is convergent

if $\displaystyle \lim_{n\rightarrow \infty}a_{n}=0.$ Otherwise it is diverges.

$$\lim_{n\rightarrow \infty}a_{n}=\lim_{n\rightarrow \infty}\frac{2+(-1)^n}{n}=0+\lim_{n\rightarrow \infty}\frac{(-1)^n}{n}$$

Can anyone please tell me how can I solve that limit. Help me please

Bernard
  • 175,478
jacky
  • 5,194

2 Answers2

3

Hint - By the triangle inequality, $|a_{n}|\le \frac{3}{n}$.

2

Use that $$\left|\frac{(-1)^n}{n}\right|\le \frac{1}{n}$$