Respuesta :

RickyChen
sin2x = 2sinxcosx
cos2x = (cosx)^2 - (sinx)^2 = 2(cosx)^2 -1 = 1- 2(sinx)^2

Any combination you want is here.
taylorj740
Sin2x-cos2x
2sinxcosx-2cos^2x-1
2cos^2x+2sinxcosx-1
I think that's how you do this one.