Question

f(x)=sin(3x)cos(x/3) , find f'(x) , show steps .

Answer 1

use the product rule
f(x)=uv
f'(x)= u'v + uv'

here u=sin(3x)
u'=3cos(3x)
v=cos(x/3)
v'=-1/3 sin (x/3)

f'(x) = 3cos(3x)*cos(x/3) +1/3 sin(3x)(-sin(x/3)

Answer 2

Thanks!