1)2sin^2(x+3p\2)≥1\2
2)ctg3x-√3≥0
sin(x+(3π/2))= - cosx
2cos^2x ≥ 1/2
cos^2x ≥ 1/4
cosx ≤ -1/2 или cosx ≥ 1/2
[b][2π/3)+2πk; (4π/3)+2πk], k ∈ Z или [(-π/3)+2πn; (π/3)+2πn], n ∈ Z[/b]
б)
ctg3x–√3 ≥ 0
ctg3x ≥ √3
0+πk< 3x ≤ (π/6)+πk, k ∈ Z
[b](π/3)*k< x ≤ (π/18)+(π/3)*k, k ∈ Z [b]