2 4. Consider the series En=2 an = Zn=2 (n-1)(n+1) . Determine if the series converges by doing the following a) (4 pts.) Use partial fraction decomposition to separate an into two fractions b) (5 pts.) Use a telescopic sum to write an expression for Sk, the k" term of the sequence of partial sums (show all your steps) c) (5 pts.) Find the limit: lim Sk , and use the definition of convergence of a series to determine if this series converges. If n-+00 it converges find its sum