Question

Найдите производную функции y=3^x*cos x

Answer 1

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