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tanC/2=1-cosC/sinC这个的推导过程,
题目详情
tanC/2=1-cosC/sinC这个的推导过程,
▼优质解答
答案和解析
左边=sin(C/2)/cos(C/2)
=2sin²(C/2)/[2sin(C/2)cos(C/2)]
=-[1-2sin²(C/2)-1]/sinC
=-(cosC-1)/sinC
=(1-cosC)/sinC=右边
命题得证
=2sin²(C/2)/[2sin(C/2)cos(C/2)]
=-[1-2sin²(C/2)-1]/sinC
=-(cosC-1)/sinC
=(1-cosC)/sinC=右边
命题得证
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