cos2x=1/2
2x = ± + 2n, n ∈ Z
x = ± +
= (-1)⁻n n, n ∈ Z
x = (-1)⁻n n, n ∈ Z
n, n ∈ Z
x = n, n ∈ Z
Х=8+3
Х=11
(11-3)=8 ответ 8 = 8
Ответ: -37.