Question

Помогите уростить 2*sin^2x-1/sinx-cosx

Answer 1

2sin^2 x-1    1-2sin^2 x   cos2x        cos^2 2x

_________=-_________=-________=-_______= -cos2x

sinx-cosx      cosx-sinx    cosx-sinx    cos2x

Answer 2

(2sin²x-1)/(sinx-cosx) = (2sin²x - sin²x - cos²x)/(sinx - cosx) =

=(sin²x - cos²x)/(sinx-cosx) = (sinx-cosx)·(sinx+cosx)/(sinx-cosx) = sinx+cosx