Question

Stationary point of $y=\frac{\log x}{x}(x>0)$ is

• A. $(1,0)$
• B. $(e,\frac{1}{e})$
• C. $(\frac{1}{e},-e)$
• D. $(\frac{1}{e^{\prime }}\frac{1}{e})$

Answer 1

The correct option is B $(e,\frac{1}{e})$

$y^{\prime }=\frac{1}{x^2}-\frac{logx}{x^2}$ $=(1-logx)\frac{1}{x^2}$
and $y^{\prime }=0$ for stationary point
$\therefore x=e$