Решить равенство
2 cos x < 1

2 cos x < 1 cos x < 1/2arccos(1/2) + 2πn < x < 2π - arccos(1/2) + 2πn, n∈Zπ/3 + 2πn < x < 2π - π/3 + 2πn, n∈Zπ/3 + 2πn < x < 5π/3 + 2πn, n∈Z