18. The series (-1)" n= 2 In(n) (a) converges absolutely (b) converges conditionally (c) diverges (d) diverges absolutely n(x - 2)n 19. The radius of convergence of the power series is R = 5n n=1 (a) (b) 2 (c) 5 (d) co (2 - 4)' 20. The interval of convergence of the power series is I = 2n n=1 (a) [3, 5] (b) (3,5) (c) [3, 5) (d) (3, 5]