Evaluate ∫C 1z2 dz , Where C : z = 1. ⇒z0 = 0 is non analytic point in C, fz = 1 & n = 1. But f'z = 0. → Then by Cauchy's Integral formula, ∫C 1z2 dz = 2πi n ! fnz0 ⇒∫C 1z2 dz = 2πi 1 ! f1z0 = 0