Giải phương trình \(1 + \sin 3x = \sin x + \cos 2x...

Câu hỏi: Giải phương trình \(1 + \sin 3x = \sin x + \cos 2x\).

A \(\left[ \begin{array}{l}
x = k\pi \\
x =- \dfrac{\pi }{2} + k\pi \\
x = \dfrac{\pi }{6} + k2\pi \\
x = \dfrac{{7\pi }}{6} + k2\pi 
\end{array} \right.\)

B \(\left[ \begin{array}{l}
x = k\pi \\
x = \dfrac{\pi }{2} + k2\pi \\
x =  \dfrac{\pi }{6} + k2\pi \\
x = -\dfrac{{7\pi }}{6} + k2\pi 
\end{array} \right.\)

C \(\left[ \begin{array}{l}
x = k\pi \\
x = -\dfrac{\pi }{2} + k2\pi \\
x = \dfrac{\pi }{6} + k2\pi \\
x = \dfrac{{7\pi }}{6} + k2\pi 
\end{array} \right.\)

D \(\left[ \begin{array}{l}
x = k\pi \\
x = \dfrac{\pi }{2} + k2\pi \\
x = - \dfrac{\pi }{6} + k2\pi \\
x = \dfrac{{7\pi }}{6} + k2\pi
\end{array} \right.\)