Question

Дана функция f(x) = sin3x•cos3x Найдите f'(x)      

A)2cos6x B)-cos6x C)3cos6x D)-2cos²2x+2sin²2x E)4sin6x

Answer 1

f(x)=sin3x*cos3x
f(x)=1/2 * 2sin3x*cos3x
f(x)=1/2* sin6x


f'(x)=(1/2 *sin6x)'=1/2 *(sin6x)' = 3cos6x 

Answer 2

 f(x) = sin3x•cos3x=1/2*2 sin3x•cos3x=1/2sin6x

f`=1/2*6cos6x=3cos6x    C