Question

qual a derivada de f(x)= sex/x

Answer 1

$\displaystyle f(x)=\frac{\sin(x)}{x}$
derivada de função racional:
$\displaystyle \left(\frac{u}{v}\right)'=\frac{u'\cdot v-v'\cdot u}{v^2}$
então:
$\displaystyle \frac{d}{dx}\left(\frac{\sin x}{x}\right)=\frac{\cos (x)\cdot x\,-\sin(x)}{x^2}=\boxed{\frac{x\cos x-\sin x}{x^2}}$