If $f(x)=\dfrac{\ln x}{x}$, then $f'(x)=$

Core Concept

The quotient rule gives $\dfrac{\frac{1}{x}\cdot x-\ln x\cdot1}{x^2}$. Since $\dfrac{1}{x}\cdot x=1$, the result is $\dfrac{1-\ln x}{x^2}$.