Помогите уростить 2*sin^2x-1/sinx-cosx
(2sin²x-1)/(sinx-cosx) = (2sin²x - sin²x - cos²x)/(sinx - cosx) =
=(sin²x - cos²x)/(sinx-cosx) = (sinx-cosx)·(sinx+cosx)/(sinx-cosx) = sinx+cosx
2sin^2 x-1 1-2sin^2 x cos2x cos^2 2x
_________=-_________=-________=-_______= -cos2x
sinx-cosx cosx-sinx cosx-sinx cos2x