2tan^2(x/2)+2=4tan(

问题描述:

2tan^2(x/2)+2=4tan(
x/2)

楼主题目错了.
应该是
2tan(x) = tan^2(x/2)+1 吧.
用用
tanx = sinx/cosx
sinx =2sin(x/2)cos(x/2)
cosx =2cos^2(x/2)-1
基本就可以解决了吧.