2sinxcosx-2sinx-cosx+1=0

2 * sin x * cos x - 2 * sin x - cos x + 1 = 0

2 * sinx * (cos x - 1) - (cos x - 1) = 0

(2 * sin x - 1) * (cos x - 1) = 0

1) 2 * sin x = 1                                  2) cos x = 1

    sin x = 0,5                                         x = 2 * π * n

    x = (-1)^N * π / 6 + π * n