2tg в квадрате x+3tgx-2=0

2tg^2x + 3tgx - 2 = 0

tgx = t

2t^2 + 3t - 2 = 0

D = 9 + 16 = 25

t1 = ( - 3 + 5) / 4 = 1/2 = 0,5

t2 = ( - 3 - 5) / 4 = - 8/4 = - 2

tgx = 0,5

x = arctg (0,5) + pik, k ∈Z

tgx = - 2

x = - arctg (2) + pik, k ∈Z