8. (15 points) Given a complex polynomial P(z) = do + diz + azz~ + .. + anz" having no multiple roots (n roots which are not the same), prove 1 P' (z) 2ni dz = numbers of zeroths of P(z) inside C P (z) where C is the contour for the integral.6. Evaluate the integral (15 points) dz (z - a)(z - b)' a # b using Cauchy theorem, where the a and b are inside the contour