#tantheta+ cottheta=4/sqrt3#
#=>tantheta+ 1/tantheta=4/sqrt3#
#=>sqrt3tan^2theta+ sqrt3=4tantheta#
#=>sqrt3tan^2theta-4tantheta+ sqrt3=0#
#=>sqrt3tan^2theta-3tantheta- tantheta+ sqrt3=0#
#=>sqrt3tantheta(tantheta-sqrt3)- (tantheta-sqrt3)=0#
#=>(tantheta-sqrt3)(sqrt3tantheta-1)=0#
When
#tantheta=sqrt3#
#=>tantheta=tan(pi/3)=tan(pi+pi/3)#
#theta=pi/3 or(4pi)/3#
When
#tantheta=1/sqrt3#
#=>tantheta=tan(pi/6)=tan(pi+pi/6)#
#theta=pi/6 or(7pi)/6#