Giải phương trình \(\sin x + \cos x = \sqrt 2 \sin 5x\).
A.\(\left[ \begin{array}{l}x = \dfrac{\pi }{{18}} + k\dfrac{\pi }{2}\\x = \dfrac{\pi }{9} + k\dfrac{\pi }{3}\end{array} \right.\)
B.\(\left[ \begin{array}{l}x = \dfrac{\pi }{{12}} + k\dfrac{\pi }{2}\\x = \dfrac{\pi }{{24}} + k\dfrac{\pi }{3}\end{array} \right.\)
C.\(\left[ \begin{array}{l}x = \dfrac{\pi }{{16}} + k\dfrac{\pi }{2}\\x = \dfrac{\pi }{8} + k\dfrac{\pi }{3}\end{array} \right.\)
D.\(\left[ \begin{array}{l}x = \dfrac{\pi }{4} + k\dfrac{\pi }{2}\\x = \dfrac{\pi }{6} + k\dfrac{\pi }{3}\end{array} \right.\)