Question

Question #5a24c

Answer 1

`x=(pi/3)n`

Explanation:

`f'(x)=-3sin (3x)* 3`
`f'(x)=-9sin (3x)`
`-9sin(3x)=0`
`sin(3x)=0`
`3x=sin^-1(0)`
`3x=pi n`
`x=(pi/3)n`