How do you find the derivative of f(x)=8sinxcosx?

1 Answer
Feb 16, 2017

f'(x)=8(cos^2x-sin^2x)=8cos2x

Explanation:

This will need the product rule:

f(x)=uv=>f'(x)=vu'+uv'

f(x)=8sinxcosx

u=8sinx=>u'=8cosx

v=cosx=>v'=-sinx

:.f'(x)=8cosxxxcosx+8sinx xx(-sinx)

f'(x)=8(cos^2x-sin^2x)=8cos2x