Ка Катя cos(x) - 3sin(x)cos(x) + 1 = 0 1 - 3tg(x) + 1 +tg(x) = 0 tg(x) - 3tg(x) + 2 = 0 tg(x) = 1 tg(x) = 2 --> x = π/4 + πk, x = arctg(2) + πk