cos210°=?
3个回答
cos210°
=cos(180º+30°)
=-cos30º
=-√3/2
相关问题
因为cos30°=√3/2,cos210°=-√3/2,所以cos210°=cos(180°+30°
cos(-210)等于多少
cos300°-sin210°=
化简:cos150°+sin210°+cos1470°+cos(-570°)
化简:cos150+sin210+cos1470+cos(-570)
[3−sin70°2−cos210°
[3−sin70°2−cos210°
求值:sin(−150°)cos(−210°)cos(−420°)cos(−600°)sin(−1050°).
tan500°和cos210°谁大
求cos190°•(−sin210°)cos350°•(−tan585°)的值.