Question

Найдите производную функции y=3^x*cos x

Answer 1

$frac{d}{dx} [3^xcos(x)]$
$3^x frac{d}{dx} [cos(x)]+cos(x) frac{d}{dx} [3^x]$
$3^x(-sin(x))+cos(x) frac{d}{dx} [3^x]$
$-3^xsin(x)+cos(x) frac{d}{dx} [3^x]$
$-3^xsin(x)+cos(x)(3^xln(3))$
$-3^xsin(x)+3^xcos(x)ln(3)$