I am having a hard time with this problem. The only thing I can think to do is change cos(x) to (1-sin^2(x)) but im not even sure how that would help. What step am I missing here?
Thank you. However, I am still having problems.
Sin(4x) * Cos(x) = 0.84
2*Sin(2x)*cos(2x) * cos(x) =0.84
2*2*Sin(x)*cos(x)*(cos^2x-sin^2x)*cos(x) = 0.84
4*sin(x)*cos^2(x)*(cos^2x-sin^2x) = 0.84
Forgive me, but I am not sure how to further simplify this problem.