解方程3x/(x²-1)+x²/2x=5/2

问题描述:

解方程3x/(x²-1)+x²/2x=5/2

题目应该错了
应该是3x/(x²-1)+)(x²-1)/2x=5/2
令t=x/(x²-1),则有:
3t+1/(2t)=5/2;
6t²+1-5t=0;
(2t-1)(3t-1)=0;
t=1/2或t=1/3;
∴x/x²-1=1/2;
x²-1-2x=0;
(x-1)²=2;
x-1=±√2;
x=1±√2;
或x/x²-1=1/3;
x²-3x-1=0;
(x-3/2)²=13/4;
x-3/2=±√13/2
x=(3±√13)/2
所有原方程的解为
x1=1+√2 x2=1-√2 x3=(3+√13)/2 x4=(3-√13)/2