Решить
а)cos4x=1
б)cos2x=-1
в)cos(x+П/3)=0

Решение
а) cos4x = 1
4x = 2πk, k∈Z
x = πk/2, k∈z
б) cos2x= -1
2x = π + 2πn, n∈z
x = π/2 + πn, n∈Z
в) cos(x +π/3)=0
x + π/3 = π/2 + πm, m∈Z
x = π/2 - π/3 + πm, m∈Z
x = π/6 + πm, m∈Z