Решите неравенство [tex] 4cos^{2} x-3\geq 0 [/tex]

A) (-3; 0) U [2; 4]
B) [-3; 0] U (2; 4)
C) (-∞; -3) U (0; 2) U (4; ∞)
D) (-3; 0] U [2; 4)

4cos²x-3≥0cos²x≥3/4|cosx|≥√3/2[cosx≥√3/2[cosx≤-√3/21)cosx≥√3/2-π/6+2πk≤x≤π/6+2πk2)cosx≤-√3/25π/6+2πk≤x≤4π/3+2πk