could somone help me do this math problem, i've got all the information i think i need, but i cannot get the right answer. its for a math make-up, would really appriciate your help. thanks.

Info:

A=rcosΘ

B=rsinΘ

Z=A+Bi = (rcosΘ+isinΘ)

tanΘ=B/A

r=sqrt((A^2)+(B^2))

Problem: Find all the square roots of the complex number Z= -1/2 - (sqrt3)/2. You can use polar coordinates but convert them back to retangular form for the answer.