cos60°/(1+sin60°) +1/tan30°
=(1/2)/(1+√3/2 )+1/(√3/3 )
=1/(2+√3)+√3
=2-√3+√3=2是*不是+cos60°/(1+sin60°) *1/tan30°=(1/2)/(1+√3/2 )*1/(√3/3 )=1/(2+√3)*√3=√3/(2+√3) =√3(2-√3)/[(2+√3)(2-√3)] =2√3-3