Answer:
Correct answer: a) -8
Explanation:
Complex Numbers
A complex number z in polar form is expressed as

The nth power of a complex number in polar form is:

If the complex number is given in rectangular form

then the values of r and θ are given by:


The given complex number is:

The value of r is:


r=2
Calculating the angle:


Since the number is in the quadrant IV, the angle is:

Thus, z is expressed in polar form as:

Calculating:

Given cos 180°=-1 and sin(-180°)=0


Correct answer: a) -8