Question

Cos2x-sinx-1=0
Помогите побыстрому пж

Answer 1

1 - sin^2 x - sin x + 1 = 0;

-sin^2 x - sin x = 0;

sin^2 x + sin x = 0;

sin x * (sin x + 1) = 0;

1) sin x = 0;

x = pi * n, n ∈ Z;

2) sin x + 1 = 0; sin x = -1;

x = -pi/2 + 2* pi * n, n ∈ Z;

Ответ: x = pi * n и x = -pi/2 + 2* pi * n, n ∈ Z.