Π(x + 5)/6 = arccos (-1/2) + 2πn или π(x + 5)/6 = - arccos (-1/2) + 2πk
π(x + 5)/6 = π - arccos (1/2) + 2πn π(x + 5)/6 = - (π - arccos (1/2)) + 2πk
π(x + 5)/6 = 2π/3 + 2πn π(x + 5)/6 = - 2π/3 + 2πk
(x + 5)/6 = 2/3 + 2n (x + 5)/6 = - 2/3 + 2k
x + 5 = 4 + 12n x + 5 = - 4 + 12k
x = -1 + 12n x = - 9 + 12k
n = 1 ⇒ x = 11 k = 1 ⇒ x = 3
Ответ: 3 - наименьший положительный корень