如何求证要过程！

11 |

1 | 2013-7-26 23:20:04 | 显示全部楼层 |阅读模式

左边=[1+cosθ+cos(θ/2)]/[sinθ+sin(θ/2)]
=[1+2cos2(θ/2)-1+cos(θ/2)]/[2sin(θ/2)cos(θ/2)+sin(θ/2)]
=[2cos2(θ/2)+cos(θ/2)]/[2sin(θ/2)cos(θ/2)+sin(θ/2)]
={cos(θ/2)[2cos(θ/2)+1]}/{sin(θ/2)[2cos(θ/2)+1]}
=cos(θ/2)/sin(θ/2)
=cot(θ/2)右边=sinθ/(1-cosθ)
=2sin(θ/2)cos(θ/2)/{1-[1-...

使用道具举报