1. 1) ctg x = 1; x ∈(- π; 2π).
x = π/4 + πk; k∈Z
x= - 3π/4; π/4; 5π/4.
2) ctgx = - √3; x∈(- π; 2π).
x = - π/6 + 2πk; k ∈Z.
x = - π/6; 5π/6.
2. 1) ctg x < - 1;x∈(- π; 2π).
- π/4 < x < 0 U 3π/4 < x < 2π U 7π/4 < x < 2π.
2) ctg x ≥ - √3; x ∈ ( - π; 2π).
- π ≤ x ≤ - π/6 U 0 ≤ x ≤5π/6 U π ≤ x ≤ 11 π/6