ctg (x + π/6) = 1
x + π/6 = arc ctg 1
x + π/6 = π/4 + kπ k ∈ Z
x = π/4 - π/6 + kπ k ∈ Z
x = π/12 + kπ k ∈ Z
ctg (x + π/6) = 1
x + π/6 = arc ctg 1
x + π/6 = π/4 + kπ k ∈ Z
x = π/4 - π/6 + kπ k ∈ Z
x = π/12 + kπ k ∈ Z