The question states:

Use the polar form and De Moivre's Theorem to simplify:

(a) (1+i)^5

_______

1 - i

So I categorised each as z1 and z2, worked out the modulus and argument of each, ( |z1| = root 2, |z2| = root 2, arg z1 = pie/4, arg z2 = - pie/4)

Carried out de moivre's theorem and got as far as the step

4cis(5pie/4)

__________

cis(-pie/4)

It would be much appreciated if anyone could help me finish it off or correct me if I've gone wrong somewhere along the line. Cheers