发布网友
共1个回答
热心网友
sin70cos50+cos70cos40
=sin70cos50+cos70sin(90-40)
=sin70cos50+cos70sin50
=sin(70+50)
=sin120
=cos30
=(√3 )/2
热心网友
sin70cos50+cos70cos40
=sin70cos50+cos70sin(90-40)
=sin70cos50+cos70sin50
=sin(70+50)
=sin120
=cos30
=(√3 )/2
热心网友
sin70cos50+cos70cos40
=sin70cos50+cos70sin(90-40)
=sin70cos50+cos70sin50
=sin(70+50)
=sin120
=cos30
=(√3 )/2
热心网友
sin70cos50+cos70cos40
=sin70cos50+cos70sin(90-40)
=sin70cos50+cos70sin50
=sin(70+50)
=sin120
=cos30
=(√3 )/2
热心网友
sin70cos50+cos70cos40
=sin70cos50+cos70sin(90-40)
=sin70cos50+cos70sin50
=sin(70+50)
=sin120
=cos30
=(√3 )/2