Numere complexe in forma trigonometrică

•  $$z=2\left(\cos \frac{5\pi }{3}+i\sin \frac{5\pi }{3}\right)$$ 

Forma trigonometrica a numărului $z=\sqrt{2}+i\ \sqrt{2}$   este:

•  $z=\cos\ \frac{3\pi}{4}+i\ \sin\ \frac{3\pi}{4}$ 

•  $z=\ 2\left(\cos\ \frac{3\pi}{4}+i\ \sin\ \frac{3\pi}{4}\right)$ 

•  $z=2\left(\sin\ \frac{\pi}{4}+i\ \cos\ \frac{\pi}{4}\right)$ 

•  $z=2\left(\cos\ \frac{\pi}{4}+i\ \sin\ \frac{\pi}{4}\right)$