I got up to the following part;
Where it says calculate I didnt quite understand what it wants so id did the following;
(1-i)^5=1-i-i^5=2-i
Modulus is;
Sqrt(2^2+1^2 = Sqrt(5)
Argument(2-i)= atan(-1/2)= -26.6
(atan(-1/2))+360= 333.4degrees
In polar form, 2-i is: Sqrt(5), theta= 333.4
Wrong. If you were going to expand these brackets, you should have (1 - i)(1 - i)(1 - i)(1 - i)(1 - i), which should give you a LOT more than 1 - i - i^5.
As you have been told already, convert to the polar form which Plato did in post 2, then use DeMoivre's Theorem, like you have been instructed.