cos(派/5)*cos(2派/5)=?顺便教我一下,派怎么打,根号怎么打出来?
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/04 05:57:06
![cos(派/5)*cos(2派/5)=?顺便教我一下,派怎么打,根号怎么打出来?](/uploads/image/z/11552494-22-4.jpg?t=cos%28%E6%B4%BE%2F5%29%2Acos%282%E6%B4%BE%2F5%29%3D%3F%E9%A1%BA%E4%BE%BF%E6%95%99%E6%88%91%E4%B8%80%E4%B8%8B%2C%E6%B4%BE%E6%80%8E%E4%B9%88%E6%89%93%2C%E6%A0%B9%E5%8F%B7%E6%80%8E%E4%B9%88%E6%89%93%E5%87%BA%E6%9D%A5%3F)
cos(派/5)*cos(2派/5)=?顺便教我一下,派怎么打,根号怎么打出来?
cos(派/5)*cos(2派/5)=?
顺便教我一下,派怎么打,根号怎么打出来?
cos(派/5)*cos(2派/5)=?顺便教我一下,派怎么打,根号怎么打出来?
原式=2sin(π/5)cos(π/5)cos(2π/5)/2sin(π/5)
=sin(2π/5)cos(2π/5)/2sin(π/5)
=2sin(2π/5)cos(2π/5)/4sin(π/5)
=sin(4π/5)/4sin(π/5)
=sin(π-π/5)/4sin(π/5)
=sin(π/5)/4sin(π/5)
=1/4
π,你就在这里复制吧
或者用搜狗输入法,输入pai,选3
根号√
先把输入法调为英文状态
然后按住Alt键
在右边小键盘输入41420即可