Question

Find all cube roots of 64 (cos 219 degrees +i sin 219 degrees)

Answer 1

The principal root is
  (64∠219°)^(1/3) = (64)^(1/3)∠(219°/3) = 4∠73°

The other two roots are 120° and 240° from this, so the three roots are
  4∠73°
  4∠193°
  4∠313°