Verified answer

1. tg(π/2 + x) = -1

-ctgx = -1

ctgx = 1

x = arcctg(1) + πn, n ∈ Z

Ответ: x = π/4 + πn, n ∈ Z

2. cosx ≥√3/2

-arccos(√3/2) + 2πn ≤ x ≤ arccos(√3/2) + 2πn, n ∈ Z

Ответ: 5π/6 + 2πn ≤ x ≤ π/6 + 2πn, n ∈ Z