trigonometry - Solve $left| cos { left( 2x right) } right| = frac { 1 }{ 2 } $

How do you solve the following equation over an unrestricted domain;
$$\left| \cos { \left( 2x \right) } \right| = \frac { 1 }{ 2 } $$

I can solve half of it;

$$\cos { \left( 2x \right) } =\frac { 1 }{ 2 } \\ x=\pi n\pm \frac { \pi }{ 6 } $$

but how do you do the other half
$$\cos { \left( 2x \right) } =-\frac { 1 }{ 2 } $$