\(\Leftrightarrow1-cos2x+\sqrt{3}sin2x=3\left(cosx+\sqrt{3}sinx\right)\)
\(\Leftrightarrow\frac{\sqrt{3}}{2}sin2x-\frac{1}{2}cos2x+\frac{1}{2}=3\left(\frac{\sqrt{3}}{2}sinx+\frac{1}{2}cosx\right)\)
\(\Leftrightarrow sin\left(2x-\frac{\pi}{6}\right)-3sin\left(x+\frac{\pi}{6}\right)+\frac{1}{2}=0\)
Đặt \(x+\frac{\pi}{6}=a\Rightarrow2x=2a-\frac{\pi}{3}\Rightarrow2x-\frac{\pi}{6}=2a-\frac{\pi}{2}\)
\(sin\left(2a-\frac{\pi}{2}\right)-3sina+\frac{1}{2}=0\)
\(\Leftrightarrow-cos2a-3sina+\frac{1}{2}=0\)
\(\Leftrightarrow2sin^2a-3sina-\frac{3}{2}=0\)
\(\Leftrightarrow...\)
