( \sqrt{8}(\cos \frac{7\pi}{4} + i \sin \frac{7\pi}{4}) )

( 2(\cos \frac{\pi}{4} + i \sin \frac{\pi}{4}) )

( \sqrt{8}(\cos \frac{\pi}{4} + i \sin \frac{\pi}{4}) )

( 4(\cos \frac{3\pi}{4} + i \sin \frac{3\pi}{4}) )