2 cos (4x+ π/3)+√3=0
cos (4x+ π/3)=-√3/2
4x+ π/3=±arccos(-√3/2)+2πn; n∈ Z
4x+ π/3=±(π-arccos(√3/2)+2πn; n∈ Z
4x+ π/3=±(π-π/6)+2πn n∈ Z
4x+ π/3=±(5π/6)+2πn; n∈ Z
4x=- π/3±(5π/6)+2πn; n∈ Z
x=- π/12±5π/24+0.5πn; n∈ Z
