Answer:
8(cos(π) +i·sin(π))
Step-by-step explanation:
The number in parentheses has a magnitude of ...
√(1^2 +(√3)^2) = √4 = 2
Then the cube of that number will have a magnitude of 8, eliminating the 2nd and 4th choices
The angle of the number in parentheses is ...
arctan(-√3/1) = -π/3
Then 3 times that angle will be -π, also π.
The number of interest has a magnitude of 8 and an angle of π, so is written in the desired form as ...
8(cos(π) +i·sin(π)) . . . . . matches the 3rd choice
