How do you solve these questions? Please give very detailed steps

3.Let sn denote the nth partial sum of the following given series. That is, sn = > ak. k=ko I. Find the least integer n such that sn approximates the series with error less than 0.01. II. Give the approximated value of the series for this n. (a) (-1)* +1 K 2k k=1 ( b ) ( - 1 ) k k (k + 1)! K = 2