Решение
а) y = 7 + √sin(x/2)
sinx/2 ≥ 0
arcsin0 + 2πn ≤ x/2 ≤ π - arcsin0 + 2πn, n ∈ Z
2πn ≤ x/2 ≤ π + 2πn, n ∈ Z
4πn ≤ x ≤ 2π + 4πn, n ∈ Z
б) y = 10 - √cos(x/3)
cosx/3 ≥ 0
- arccos0 + 2πk ≤ x/3 ≤ arccos0 + 2πk, k ∈ Z
- π/2 + 2πk ≤ x/3 ≤ π/2 + 2πk, k ∈ Z
- 3π/2 + 6πk ≤ x ≤ 3π/2 + 6πk, k ∈ Z