What is the derivative of sin(x)(cos(x)-2)?
just use the product rule
if
y = uv,
y' = u'v + uv'
y = sinx(cosx-2)
y' = (cosx)(cosx-2) + (sinx)(-sinx)
= cos^2 x - 2cos x - sin^2 x
you can play with that some if you want
cos 2x - 2cos x
2cos^2 x - 2cos x - 1
etc.