化简cos100°cos40°+sin80°sin40°
来源:学生作业帮助网 编辑:作业帮 时间:2024/05/24 07:15:00
化简cos100°cos40°+sin80°sin40°
化简cos100°cos40°+sin80°sin40°
化简cos100°cos40°+sin80°sin40°
=cos(90+10)cos40+sin(90-10)sin40
=-sin10cos40+cos10sin40
=sin(40-10)
=1/2
化简cos100°cos40°+sin80°sin40°
化简cos100°cos40°+sin80°sin40°
化简cos100°cos40°+sin80°sin40°
=cos(90+10)cos40+sin(90-10)sin40
=-sin10cos40+cos10sin40
=sin(40-10)
=1/2