(i)[3]
Write $\dfrac{iw}{z}$ in the form $x + iy$, showing every step of your working and giving exact values for $x$ and $y$.
(ii)[4]
Calculate $wz$ and then, by using arguments, show that $\tan^{-1}\!\left(\frac{3}{5}\right) + \tan^{-1}\!\left(\frac{1}{4}\right) = \frac{1}{4}\pi$.