Фа Фарид tg(π + x) + 2tg(π/2 + x) + 1 = 0 tg(x) - 2ctg(x) + 1 = 0 tg(x) + tg(x) - 2 = 0 (x ≠ πk). tg(x) = 1; tg(x) = -2 --> x = π/4 + πk; x = -arctg(2) + πk, k - целое.