Sinx-√2 sin3x=-sin5x

cos (70°+x) cos (x-20°) = 1/2

1) Sinx - √2Sin3x + Sin5x = 0 2Sin3xCos2x - √2Sin3x = 0 Sin3x (Cos2x - √2) = 0 Sin3x = 0 или Cos2x - √2 = 0 3x = πn, n∈Z Cos2x = √2 x = πn/3, n ∈Z нет решений. 2) Сos (70°+x) Cos (x - 20°) = 1/2 Sin (20° - x) Cos (20° - x) = 1/2 |*2 2Sin (20° - x) Cos (20° - x) = 1 Sin (40° - 2x) = 1 40° - 2x = 90° + 360°*n, n ∈Z 2x = - 50° - 360°n, n∈Z x = - 25° - 180°n, n ∈Z