This problem has driven me mad for 2 days now. The directions are to rewrite the function in terms of the first power of the cosine (that is, write it such that there are no sines, tangents, etc., and such that there are no powers on any of the cosines greater than 1).

The original problem: sin^4 (x) * cos^4(x)

testing the math tags: $\displaystyle sin^4 (x) * cos^4 (x)$

I have two pages of running in circles- any and all help is very much appreciated.