cos20°cos10°-cos70°cos80°
来源：学生作业帮助网 编辑：六六作业网 时间：2024/12/22 17:15:42
cos20°cos10°-cos70°cos80°cos20°cos10°-cos70°cos80°cos20°cos10°-cos70°cos80°原式=cos20°cos10°-sin20°sin
cos20°cos10°-cos70°cos80°
cos20°cos10°-cos70°cos80°
cos20°cos10°-cos70°cos80°
原式=cos20°cos10°-sin20°sin10°
=cos(20+10）°
=cos30°
=√3/2
cos20°cos10°-cos70°cos80°
=cos20°cos10°-cos(90°-20°)cos(90°-10°)
=cos20°cos10°-sin20°sin10°
=c0s30°
= 二分之根号三
cos20°cos10°-cos70°cos80°
求值:cos20°/(cos70°-2cos10°)
cos20°+cos70°=
数学函数化简题2cos10°-sin20°/cos20°=?sin40°+2cos70°/sin50°=?
cos20°cos70°sin50°=?
cos20*sin50*cos70/cos10=
求值 cos10°cos20°cos40°
cos10°—cos20°怎么算?
cos20°cos70°—sin20°sin70°=
计算：cos20°cos70°－sin20°sin70°
-cos70°cos20°-sin110°sin20°=
求值：（2sin80°-cos70°）/cos20°
求(sin40°+cos10°)/cos20° =(cos50°+cos10°)/cos20°
cos70°cos10°+sin70°sin10°的值,
(2cos70°+根号3sin10°)/cos10°
化简cos20/cos70-2cos10=cos20/(cos70-2cos10)=?
=[cos10+(cos10-cos70)]/cos20 =[cos10+2sin40*sin30]/cos20 怎么转换而来的,
(2cos10-sin20)/cos20 =(2cos10-sin20)/cos20 =[cos10+(cos10-cos70)]/cos20 =[cos10+2sin40*sin30]/cos20cos10-cos70=>2sin40*sin30 怎么过去的?