If $y = \frac{1}{x}$, what is $\frac{d^2y}{dx^2}$?

Explanation

1. 01

   $y = x^{-1}$, so $\frac{dy}{dx} = -x^{-2}$.

2. 02

   $\frac{d^2y}{dx^2} = 2x^{-3} = \frac{2}{x^{3}}$.