3tg^2 4x - 2ctg (п/2 - 4 х) = 1

3tg²4x-2ctg (π-4x) = 1

3tg²4x-2tg4x-1=0

Обозначим tg4x=y.

3y²-2y-1=0

D=4+12=16=4²

y₁ = (2-4) / 6=-2/6=-1/3

y₂=6/6=1

tg4x=-1/3

4x=arctg (-1/3) + πn

4x=-arctg1/3+πn

x=-¹/₄ arctg1/3 + (π/4) n

tg4x=1

4x=arctg1+πn

4x=π/4 + πn

x=π/16 + (π/4) n