ĐK $sin2x \not=0$
PT \Leftrightarrow $\dfrac{\sqrt{3}}{cos^2x}-2\sqrt{3}=2cotx+2-\dfrac{4}{sin2x}-2$
\Leftrightarrow $\sqrt{3}(\dfrac{1}{cos^2x}-2)=2(\dfrac{cosx}{sinx}-\dfrac{1}{sinxcosx})$
\Leftrightarrow $\sqrt{3}.\dfrac{cos2x}{cos^2x}=2.\dfrac{sinx}{cosx}$
\Leftrightarrow $\sqrt{3}.cos2x-sin2x=0$