# How do you find the derivative of  lnx / x?

$\frac{1 - \ln x}{x} ^ 2$
$f \left(x\right) = \ln \frac{x}{x}$
$f ' \left(x\right) = \frac{x \cdot \frac{1}{x} - \ln x \cdot 1}{x} ^ 2$ (Quotient rule and standard differential)
$= \frac{1 - \ln x}{x} ^ 2$