作业帮 > 数学 > 作业

计算cos(35°+x)cos(25°-x)-cos(55°-x)sin(25°-x)=______.

来源:学生作业帮 编辑:神马作文网作业帮 分类:数学作业 时间:2024/11/06 05:54:32
计算cos(35°+x)cos(25°-x)-cos(55°-x)sin(25°-x)=______.
计算cos(35°+x)cos(25°-x)-cos(55°-x)sin(25°-x)=______.
cos(35°+x)cos(25°-x)-cos(55°-x)sin(25°-x)
=cos(35°+x)cos(25°-x)-sin(35°+x)sin(25°-x)
=cos(35°+x+25°-x)
=cos60°
=
1
2.
故答案为:
1
2.