作业帮sinA / cos(A/2) = sinB / cos(B/2) = sinC / cos(C/2)为什么等于sinA/2=sinB/2=sinC/2
来源：学生作业帮助网 编辑：作业帮 时间：2024/11/05 20:49:02
sinA / cos(A/2) = sinB / cos(B/2) = sinC / cos(C/2)为什么等于sinA/2=sinB/2=sinC/2
sinA / cos(A/2) = sinB / cos(B/2) = sinC / cos(C/2)为什么等于sinA/2=sinB/2=sinC/2
sinA / cos(A/2) = sinB / cos(B/2) = sinC / cos(C/2)为什么等于sinA/2=sinB/2=sinC/2
sin(x)=2sin(x/2)cos(x/2).代入即得.