I need to see the steps and answer to this trig. question, just the steps and answer please!?

Question

Express the function as a Trigonometric function of x.
sin 4x

Theres no need to explain why your doing it, that only confuses me, just show me the steps and answer please. I can then apply that to questions in the same form or sense of the matter.

Answer 1

sin(4x)
=sin2(2x)
=2sin2xcos2x
2sinxcosx(cos^2 x-sin^2 x)

Hint:
sin 2a=2 sina cos a

Answer 2

Use trig identity
sin 2X=2 sinX cosX

sin(4x)
=sin2(2x) (factor)
=2sin2xcos2x (use identity)
2sinxcosx(cos^2 x-sin^2 x)