1) tg x = z
z² - (1 - √3) z + √3 ≤ 0
D = (1 - √3)²
z1 = √3 или z = 1
-∞ + 1 - √3 + +∞
1 ≤ tg x ≤ √3
π/4 + πk ≤ x ≤ π/3 + πk , k ∈Z
2)tg x = z
(z - 1) ( z² - 1/4 z - 3/4) ≤ 0
z - 1 = 0 z² - 1/4 z - 3/4 = 0
z = 1 z = 1 или z = -3/4
-∞ + -3/4 - 1 + +∞
- - +
z ≤ -3/4
tg x ≤ -3/4
-π/2 + πk ≤ x ≤ -arc tg 3/4 + πk , k∈Z