alright. here we go. a long one.
verify : sin^5xcos^2x = (cos^2x-2cos^4x+cos^6x)sinx

Question

alright. here we go. a long one. 
verify : sin^5xcos^2x = (cos^2x-2cos^4x+cos^6x)sinx

psymon · Answer

Turn all but one of the sines into cosines using the pythagorean identity and then multiply it out. 

$$\sin^{2}x + \cos^{2}x = 1$$
$$\sin^{2}x = 1-\cos^{2}x$$

anonymous · Answer

Mmm.. do i factor anything out first?

psymon · Answer

Well, you first rewrite it like this:

$$\sin^{2}x = 1-\cos^{2}x \implies \sin^{5}xcos^{2}x= sinx(1-\cos^{2}x)^{2}(\cos^{2}x)$$Just dont multiply in that sinx, keep it out. If you only multiply out the cosines you should have it.

anonymous · Answer

alright, thanks!

psymon · Answer

Yep, np ^_^