Question

Prove: sin θ - sin θ•cos2 θ = sin3 θ. You must show all work.

Answer 1

http://openstudy.com/study#/updates/53e0f41ce4b002c9d80341f0

Answer 2

how do you get 1-cos^2x?

Answer 3

my mistake
sinx( 1- cos^2x)
cos^2x + sin^2x = 1
so 1- cos^2x = sin^2x
sinx * sin^2x = sin^3x

Answer 4

I thought It was cos2x not cos^2x

Answer 5

ooops sorry I didnt make that clear

Answer 6

but still, how do I get 1-cos^2x?