sin100°(1+根号三tan10°)=

来源:学生作业帮助网 编辑:六六作业网 时间:2024/12/25 10:06:28
sin100°(1+根号三tan10°)=sin100°(1+根号三tan10°)=sin100°(1+根号三tan10°)=答:sin100°(1+√3tan10°)=sin100°[1+√3(si

sin100°(1+根号三tan10°)=
sin100°(1+根号三tan10°)=

sin100°(1+根号三tan10°)=
答:
sin100°(1+√3tan10°)
=sin100°[1+√3(sin10°/cos10°)]
=sin100°[(cos10°+√3sin10°)/cos10°]
=sin100°[2sin(30°+10°)/cos10°]
=(2sin80°sin40°)/cos10°
=(2cos10°sin40°)/cos10°
=2sin40°

sin50(1+√3tan10)
=sin50[1+√3(sin10/cos10)]
=sin50[(cos10+√3sin10)/cos10]
=sin50[2sin(30+10)/cos10]
=(2sin50sin40)/cos10°
=(2cos40°*sin40°)/cos10°
=sin80°/cos10°
=cos10°/cos10°
=1