#color(red)((1-tan^2 x))tan 2x=2sqrt3 ?#
#tan (a+b)=(tan a+tan b)/(1-tan a*tan b)#
#tan (x+x)=tan(2x)=(tan x+tan x)/(1-tan x*tan x)#
#tan 2x=(2tan x)/(1-tan^2 x)#
#color(red)(1-tan^2 x)=(2 tan x)/(tan 2x)#
#"let us write the equation again"#
#((2 tan x)/cancel((tan 2x)))cancel(tan 2x)=2sqrt3#
#"yields :"#
#cancel(2) tan x=cancel(2) sqrt 3#
#tan x=sqrt3#