Question

integrala din xsinx = ?

Answer 1

$\int\ {x*sin x} \, dx = \int\ {x*(-cos x)'} \, dx$
Integram prin parti
$-x*cosx - \int\ {1*(-cosx)} \, dx = -x*cosx + \int\ {cosx} \, dx =$
$= -x*cosx + sinx + C$