超越方程一例已知 f(x)=xe−xf(x)=xe^{-x}f(x)=xe−x以及g(x)=x−1lnxg(x)=x^{-1}\ln xg(x)=x−1lnx 如果y=ay=ay=a和y=f(x)y=f(x)y=f(x)以及y=g(x)y=g(x)y=g(x)共有三个交点(x1,a),(x2,a),(x3,a)(x_1,a), (x_2,a), (x_3,a)(x1,a),(x2,a),(x3,a) 且x1<x2<x3 x_1 \lt x_2 \lt x_3 x1<x2<x3 证明: x22=x1x3 x^2_2 = x_1x_3 x22=x1x3 ...