Please, help me I really need help on this problem. Thank you so much for all your help.

Question: Find the radius of convergence and interval of convergence for
sum(n=1to infinity)(-1)^n-1 multiply by n(x-1)^n/(n^2+1)2^n

Thank you again

See:

http://www.jiskha.com/display.cgi?id=1303370394