If $z=\sqrt{2}\mathrm{cis}\theta$, find the modulus and argument of $2z$ $iz$ $(1-i)z$

Question

Accepted Answer

(a) $ 2\sqrt{2}, \theta$ ; (b) $ \sqrt{2}, \frac{\pi}{2} + \theta$; (c) $ 2, \theta-\frac{\pi}{4}$.

Obtaining modulus and argument