1.

This series converges by Leibniz's Criterion since and . But the absolute value diverges by the integral test.

2. Eliminate the common factors and compare with

3. We see that

which converges by any number of tests, most handily the Root or Ratio. And therefore since the absolute value of the kernel converges so does the original series, thus absolute convergent.

4. Diverges by the n-th term test

5. Converges by limit comparison test with