# tan x = (√3) / (1+4cosx)#
# =>sin x/cosx = (√3) / (1+4cosx)#
#=>sinx+4sinxcosx=sqrt3cosx#
#=>4sinxcosx=sqrt3cosx-sinx#
#=>2sinxcosx=sqrt3/2cosx-1/2sinx#
#=>sin2x=sin60^@cosx-cos60^@sinx#
#=>sin2x=sin(60^@-x)#
#=>2x=60^@-x#
#=>3x=60^@#
#=>x=20^@#
Again #sin2x=sin(60^@-x)#
#=>sin(180-2x)=sin(60^@-x)#
#=>180-2x=60^@-x#
#=>2x-x=180^@-60^@=120^@#
#=>x=120^@#