Tg^2x-1=0 решите и еще этот ctg^2x-3=0

Tg²x = 1

tgx = ±1
x = ±π/4 + πn, n ∈ Z (или x = -π/4 + πn, n ∈ Z и x = π/4 + πn, n ∈ Z)

ctg²x - 3 = 0
ctg²x = 3
ctgx = ±√3
x = ±π/6 + πn, n ∈ Z (или x = π/6 + πn, n ∈ Z и x = -π/6 + πn, n ∈ Z).