(tan30°+tan45°)/(1-tan30°tan45°)-2sin60°-sin^2 40°-cos^2 40°
问题描述：
(tan30°+tan45°)/(1-tan30°tan45°)-2sin60°-sin^2 40°-cos^2 40°
答
原式=(√3/3+1)/(1-√3/3×1)-2×√3/2-(sin^2 40°+cos^2 40°)
=(3+√3)/(3-√3)-√3-1
=2+√3-√3-1
=1