Question

Find the radius and the interval of convergence for:

Answer 1

\[\sum_{k=1}^{\infty} [ \frac { (-1)^k (\frac{ x+1 }{ 2 }) ^k}{ k } ]\]

Answer 2

this is alternating series , so it is little complicated

Answer 3

we have absolute convergence, another kind of convergence , and divergence ; three option

Answer 4

Use ratio test