Finding a Power of a Complex Number In Exercises $65-80$ , use DeMoivre's Theorem to find the indicated power of the complex number. In the figure you see a complex number z whose absolute value is about the sixth root … finding the power of a complex number z=(3+i)^3 I know the answer, i need to see the steps worked out, please Answer by ankor@dixie-net.com(22282) (Show Source): You can put this solution on YOUR website! `81^(1"/"4)[cos\ ( 60^text(o))/4+j\ sin\ (60^text(o))/4]`. By the ratio test, the power series converges if lim n!1 n c n+1(z a) +1 c n(z a)n = jz ajlim n!1 c n+1 c n jz aj R <1; (16) where we have de ned lim n!1 c n+1 c n = 1 R: (17) R a jz The power series converges ifaj