Điều kiện $\sin 2x \ne 0 \Leftrightarrow ...$PT $\Leftrightarrow 8\sin 2x \sin x \cos x =\sqrt 3\cos x +\sin x$$\Leftrightarrow 4\sin 2x \cos 2x = \sqrt 3\cos x +\sin x$$\Leftrightarrow 2\sin 4x =\sqrt 3\cos x +\sin x$$\Leftrightarrow \sin 4x =\dfrac{\sqrt 3}{2}cos x +\dfrac{1}{2}\sin x$$\Leftrightarrow \sin 4x = \sin (x +\dfrac{\pi}{3})$ tự làm nốt
Đề chuẩn $VT=8\cos 2x$Điều kiện $\sin 2x \ne 0 \Leftrightarrow ...$PT $\Leftrightarrow 8\
cos 2x \sin x \cos x =\sqrt 3\cos x +\sin x$$\Leftrightarrow 4\sin 2x \cos 2x = \sqrt 3\cos x +\sin x$$\Leftrightarrow 2\sin 4x =\sqrt 3\cos x +\sin x$$\Leftrightarrow \sin 4x =\dfrac{\sqrt 3}{2}cos x +\dfrac{1}{2}\sin x$$\Leftrightarrow \sin 4x = \sin (x +\dfrac{\pi}{3})$ tự làm nốt