Hi i need help for calcul with a Moivre's theorem:

( 1/2 ( -1 - i√3 )) ^3
thanks for your help

convert (x,y) to (r,θ)

1/2 ( -1 - i√3 ) = (1,4π/3)

(re)n = rneinθ

(1,4π/3)3 = (13,4π) = (1,4π)
in (x,y) that's (1,0)