Giải phương trình: sin x +pi / 6 - sin 2x = 0
Giải thích
Ta có:
\(\sin \left( {x + \frac{\pi }{6}} \right) - \sin 2x = 0\,\,\, \Leftrightarrow \,\,\,\sin \left( {x + \frac{\pi }{6}} \right) = \sin 2x\)
\( \Leftrightarrow \,\,\,\left[ \begin{array}{l}x + \frac{\pi }{6} = 2x + k2\pi \\x + \frac{\pi }{6} = \pi - 2x + k2\pi \end{array} \right.\)\( \Leftrightarrow \,\,\,\left[ \begin{array}{l}x = \frac{\pi }{6} - k2\pi \\x = \frac{{5\pi }}{{18}} + k\frac{{2\pi }}{3}\end{array} \right.,\,k \in \mathbb{Z}\)