Question

решить уравнения 2 cos^2 2x - 3 = sin 2x(1 - 2sin 2x)

Answer 1

2 cos^ 2x - 3 = sin2x - 2 sin^2 2x;
2 cos^2 2x + 2 sin^ 2x - 3 - sin 2x = 0;
2(cos^2 2x + sin^2 2x) - 3 - sin 2x= 0;
2* 1 - 3 - sin 2x = 0;
- 1 - sin 2x = 0;
sin 2x = -1;
 2x = - pi/2 + 2pi k;
 x = - pi/4 + pi k; k-Z