Answer
$ 1-\displaystyle \frac{2}{x^{3}}$
Work Step by Step
Written in exponential form,
... sum/difference rule...
$f^{\prime}(x)=\displaystyle \frac{d}{dx}[x]+\frac{d}{dx}[x^{-2}]$
... power rule...
$=1+(-2x^{-3})$
$=1-2x^{-3}$
$=1-\displaystyle \frac{2}{x^{3}}$
