Решите уравнение 4sin²x-2,5sin2x+6cos²x=3

4sin²x - 2,5sin2x + 6cos²x = 3
4sin²x - 2,5sin2x + 4cos²x + 2cos²x = 3
-2,5sin2x  + 2cos²x = 2
-2,5sin2x + 1 + cos2x = 2
-2,5sin2x + cos2x = 1
2cos2x - 5cos2x = 2
2/√29 cos2x - 5/√29 cos2x = 2/√29
sin(γ - 2x) = 2/√29
sin(arcsin(2/√29) - 2x) = 2/√29
arcsin(2/√29) - 2x = (-1)^n arcsin(2/√29) + πn, n ∈ Z
- 2x = (-1)^n arcsin(2/√29) - arcsin(2/√29) + πn, n ∈ Z
x = -(-1)^n arcsin(2/√29)/2 + arcsin(2/√29)/2 + πn/2, n ∈ Z