Find the sum of the series and its radius of convergence sig

Find the sum of the series and its radius of convergence. sigma_n = 1^infinity (-1)^n + 1 (x - 1)^n/n = R = Use 50 terms of the series to approximate the sum when x = 1/3. (Round your answer to six decimal places.) sigma_n = 1^infinity (-1)^n + 1 (-2/3)^n/n Determine what the approximation represents and how good the approximation is. sigma_n = 1^50 (-1)^n + 1 (-2/3)^n/n