sin([tex] \pi /3-2x[/tex])*cos([tex] \pi /3-2x[/tex]) [tex] \geq [/tex][tex]- \sqrt{3}/4 [/tex]

1/2sin(2π/3-4x)≥-√3/4sin(2π/3-4x)≥-√3/2sin(4x-2π/3)≤√3/22π/3+2πn≤4x-2π/3≤7π/3+2πn4π/3+2πn≤4x≤3π+2πnπ/3+πn/2≤x≤3π/4+πn/2,n∈z