Question

найди f'(π) если f(x)=(5x+12)×cosx​

Answer 1

$f(x)=(5x+12)\cos x$

$f'(x)=(5x+12)'\cos x+(5x+12)(\cos x)'$

$f'(x)=5\cos x+(5x+12)(-\sin x)$

$f'(x)=5\cos x-(5x+12)\sin x$

$f'(\pi )=5\cos \pi -(5\pi +12)\sin \pi =5\cdot(-1) -(5\pi +12)\cdot0 =-5-0=-5$

Ответ: -5