Question

Find the cube roots of 8(cos 216° + i sin 216°).

Answer 1

you should use DeMoivre's theorem for complex numbers in their polar form

Answer 2

\[r^3=8 \longrightarrow r=2\]
\[3\theta = 216 + n360\]
so solve this for n=0,1,2...
to generate all the three roots