A cura di: Administrator

$f(x) = frac{xsin x}{1 – x}$; $f'(x) = frac{[1cdot sin x + x (cos x)] (1 – x) – (xsin x) (-1)}{(1 – x)^2} =$ $frac{(sin x + xcos x) (1 – x) + xsin x}{(1 – x)^2} =$ $frac{sin x + xcos x -xsin x – x^2cos x + x sin x}{(1 – x)^2} =$ $frac{sin x + xcos x – x^2cos x}{(1 -x)^2} =$