Problem

1) Examine $\sum_{n=1}^{\infty} \frac{\operatorname{tg} \frac{1}{n^{2}}}{n+3}$ for convergence

Answer

Expert–verified
Hide Steps
Answer

\(\boxed{\text{The series converges}}\)

Steps

Step 1 :\(S = \sum_{n=1}^\infty \frac{\operatorname{tg} \frac{1}{n^2}}{n+3}\)

Step 2 :Compare with \(\sum_{n=1}^\infty \frac{1}{n^2}\), which converges by the p-series test with p=2

Step 3 :Use the comparison test: \(0 \leq \frac{\operatorname{tg} \frac{1}{n^2}}{n+3} \leq \frac{1}{n^2}\) for all n

Step 4 :Since \(\sum_{n=1}^\infty \frac{1}{n^2}\) converges, so does \(\sum_{n=1}^\infty \frac{\operatorname{tg} \frac{1}{n^2}}{n+3}\) by the comparison test

Step 5 :\(\boxed{\text{The series converges}}\)

link_gpt