2sinA30°+3tan30°+tan45°
问题描述:
2sinA30°+3tan30°+tan45°
答
2sin30°+3tan30°+tan45°
=2×½+3×√3/3+1
=1+√3+1
=2+√3cos²45°+tan60°cos30°cos²45°+tan60°cos30°=﹙√2/2﹚²+√3×√3/2=½+3/2=2已知2cosA-√3=0,求锐角A的度数2cosA-√3=0cosA=√3/2∴锐角A=30°