#### Answer

$\displaystyle w' = -\frac{1.4}{z^{2.4}} - \frac{\pi}{2z^{\frac{3}{2}}}$

#### Work Step by Step

$w =\frac{1}{z^{1.4}} + \frac{\pi}{\sqrt z}$
$w = z^{-1.4} + \pi z^{-\frac{1}{2}}$
$w' = -1.4z^{-2.4} + \pi (-\frac{1}{2}z^{-\frac{3}{2}})$
$w' = -\frac{1.4}{z^{2.4}} - \frac{1}{2} \pi \frac{1}{z^{\frac{3}{2}}}$