1. ## simplify expression

sin 2x - cos 2x sin 2x

cos x - cos x sin 2x

can someone told me step by step how to simplify these two expressions?

2. Originally Posted by alessandromangione
sin 2x - cos 2x sin 2x

cos x - cos x sin 2x

can someone told me step by step how to simplify these two expressions?
It helps a lot to know that sin(2x)= 2 sin(x) cos(x) and that $cos(2x)= cos^2(x)- sin^2(x)$. You can also use $cos(2x)= 2cos^2(x)- 1$ and $cos(2x)= 1- 2sin^2(x)$.