use DeMoivre's Theorem to find cubic roots of 64( cos pi/5 + isin pi/5)?

Question

pi=3.1415...
i= complex number show work the 3 solutions.

Answer 1

64^(1/3) [cos ((π/5+ 2πk) )/ 3 + i sin( (π/5+2πk)) / 3 ]
k = 0 ,1 , 2
Giving:-
4 ( cos π/5 + i sin π/5 )
4 ( cos 11π/5+ i sin 11π/5 )
4 ( cos 21π/5 + i sin 21π/5 )