# How do you find the derivative of ln(1/x)?

$\frac{d}{\mathrm{dx}} \ln \left(\frac{1}{x}\right) = - \frac{1}{x}$
Let $y = \ln \left(\frac{1}{x}\right) \implies$
$y = \ln 1 - \ln x$
$\therefore y = - \ln x$
$\therefore \frac{\mathrm{dy}}{\mathrm{dx}} = - \frac{1}{x}$