Evaluate:
It is given in the question that,
=
= [- 1 – 1]3
= (- 1)3 [1 + i]3
= - [13 + i3 + 3 × 1 × i (1 + i)]
= - [1 + i3 + 3i + 3i2]
= - [1 – i + 3i – 3]
= - [- 2 + 2i]
= 2 – 2i