$1-\operatorname{Cos}2x=2{{\operatorname{Sin}}^{2}}x,\operatorname{Sin}2x=2\operatorname{Sin}x\operatorname{Cos}x\Rightarrow \frac{1-\operatorname{Cos}2x}{\operatorname{Sin}2x}=\frac{2{{\operatorname{Sin}}^{2}}x}{2\operatorname{Sin}x\operatorname{Cos}x}\xrightarrow{\operatorname{Sin}x\ne 0}\tan x=\sqrt{3}=\tan \frac{\pi }{3}\Rightarrow x=k\pi +\frac{\pi }{3}$