高一数学,急!追加二十
来源:学生作业帮 编辑:大师作文网作业帮 分类:数学作业 时间:2024/11/20 02:18:05
高一数学,急!追加二十
化简:sin130度(1减 根号3 tan170度)
化简:sin130度(1减 根号3 tan170度)
√代表根号
sin130°(1-√3tan170°)
=sin50°(1+√3tan10°)
=sin50°(1+√3sin10°/cos10°)
=sin50°(cos10°+√3sin10°)/cos10°
=2sin50°(1/2 cos10°+√3/2 sin10°)/cos10°
=2sin50°cos(60°-10°)/cos10°
=2sin50°cos50°/cos10°
=sin100°/cos10°
=cos10°/cos10°
=1
sin130°(1-√3tan170°)
=sin50°(1+√3tan10°)
=sin50°(1+√3sin10°/cos10°)
=sin50°(cos10°+√3sin10°)/cos10°
=2sin50°(1/2 cos10°+√3/2 sin10°)/cos10°
=2sin50°cos(60°-10°)/cos10°
=2sin50°cos50°/cos10°
=sin100°/cos10°
=cos10°/cos10°
=1