Giải phương trình \(2\cos x - 1 = 0\).
A.\(x = \pm \frac{\pi }{3} + k2\pi \,\,\left( {k \in \mathbb{Z}} \right)\).
B.\(x = \pm \frac{\pi }{6} + k2\pi \,\,\left( {k \in \mathbb{Z}} \right)\).
C.\(x = \pm \frac{\pi }{3} + k\pi \,\,\left( {k \in \mathbb{Z}} \right)\).
D.\(x = \pm \frac{\pi }{6} + k\pi \,\,\left( {k \in \mathbb{Z}} \right)\).