Answer
$ 0.022x^{-2.1}$
Work Step by Step
$f''(x)=\displaystyle \frac{d}{dx}\left[\frac{df}{dx}\right]=\frac{d^{2}f}{dx^{2}}$
$\displaystyle \frac{dy}{dx}=\frac{d}{dx}[0.2x^{-0.1}]= 0.2(-0.1x^{-0.1-1})=-0.02x^{-1.1}$
$\displaystyle \frac{d^{2}y}{dx^{2}}=\frac{d}{dx}[ -0.02x^{-1.1}]=-0.02(-1.1x^{-2.1})$=$ 0.022x^{-2.1}$
