Question

Which expression is a sixth root of -1 + i√3?

A.6rt2(cos(90°) + isin(90°))
B. 6rt2 (cos(60°) + isin(60°))
C. 6rt2 (cos(300°) + sin(300°))
D. 6rt2 (cos(20°) + isin(20°))

Answer 1

Answer: D

Explanation:

By De Moivre's theorem, the argument will be 120 degrees, which is the same as the argument of
`-1+i \sqrt 3`.

This isn't the case for the other 3 options.