A cura di: Administrator

$f(x) = (x + log x) (x – 1)$
$f'(x) = (1 + 1/x) (x – 1) + (x + log x) cdot 1 =$ $frac{(x + 1)}{x}cdot (x – 1) + (x + log x) =$ $frac{x^2 – 1}{x} + (x + log x) =$ $frac{x^2 – 1 + x^2 + xlog x}{x} = 2x + log x -frac{1}{x}$