Question

Find $\frac{d^{2}y}{d{x}^2},$ if $y=\log x$

Answer 1

$\begin{array}{c}y=\log x\\ \frac{dy}{dx}=\frac{1}{x}\\ \frac{d^{2}y}{d{x}^2}=\frac{-1}{x^2}\end{array}$