cos30°-sin45°/(sin60°+cos45°) +(tan45°+tan60°)/tan45°-tan60°

问题描述:

cos30°-sin45°/(sin60°+cos45°) +(tan45°+tan60°)/tan45°-tan60°

倍角公式,书上有

=(√3/2-√2/2)/(√3/2+√2/2)+(1+√3)/(1-√3)
=(√3-√2)/(√3+√2)-(√3+1)/(√3-1)
=(√3-√2)²-(√3+1)²/2
=3-2√6+2-(3+2√3+1)/2
=5-2√6-2-√3
=3-2√6-√3