SOLUTION: how do you prove that 1/4(sin4x) = sinx(cosx^3)-cosx(sinx^3)

Algebra ->  Trigonometry-basics -> SOLUTION: how do you prove that 1/4(sin4x) = sinx(cosx^3)-cosx(sinx^3)       Log On


   

Question 613414: how do you prove that 1/4(sin4x) = sinx(cosx^3)-cosx(sinx^3)
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
how do you prove that 1/4(sin4x) = sinx(cosx^3)-cosx(sinx^3)
**
Start with left side:
1/4(sin4x)
=1/4[2sin2xcos2x]
=1/2[2sixcosx(cos^2x-sin^2x)
=sinxcos^3x-cosxsin^3x
Verified:
left side=right side