Answer
$5\sqrt {3}$
Work Step by Step
$\frac{d}{dx}(h(\sin x))|_{x=\frac{\pi}{6}}=h'(\sin\frac{\pi}{6})\times \cos \frac{\pi}{6}$
(That is, the derivative of the main function$\times$ the derivative of the inner function)
$=h'(0.5)\times\frac{\sqrt 3}{2}=\frac{10}{2}\sqrt 3=5\sqrt 3$