Complex numer express (1+i)^9/(1-i)^9

[kelvin macks]

Homework Statement

i express (1+i)^9 as 16surd9(cos (9pi/4) +i sin (9pi/4)) and (1-i)^9 as 16surd9(cos (-9pi/4) -i sin (9pi/4)) , then i divide both, but my ans is (1+i)/(1-i) , which is different with the ans given, why can't i do in this way? i have attached the sample ans

Homework Equations

The Attempt at a Solution

 

[D H]

First off, what do you mean by "16surd9"? Two wrongs sometimes cancel to make a right, as is the case here. But you should show how you derived that factor. There's a misunderstanding on your part.

Next, you didn't show how you "divided both". You showed the answer sheet. Show your work.