Chapter 12.11, Problem 1P

Finish the solution of equation (11.2) when $s=-2.$ Write your solution in closed form as in (11.6). To avoid confusion with the $a_n$ values we found when $s=-1$, you may want to call the coefficients in your series $a_n^{\prime }$ or $b_n$; however, this is not essential as long as you realize that there are two separate problems, one when $s=-1$ and one when $s=-2,$ and each series has its own coefficients.