求2x-1⼀x-4x⼀(2x2(平方)-1)=3的所有根的确平方之和

2025-12-04 16:02:31
推荐回答(1个)
回答1:

2x-1/x-4x/(2x^2-1)=3
(2x^2-1)/x-4x/(2x^2-1)-3=0
设(2x^2-1)/x=a
a-4/a-3=0
a^2-3a-4=0
(a-4)(a+1)=0
a=4或a=-1
(1)a=4
(2x^2-1)/x=4
2x^2-4x-1=0
x1+x2=2,x1*x2=-1/2
x1^2+x2^2=(x1+x2)^2-2x1x2=5
(2)a=-1
(2x^2-1)/x=-1
2x^2+x-1=0
x3+x4=-1/2,x3*x4=-1/2
x3^2+x4^2=(x3+x4)^2-2x3x4=5/4

x1^2+x2^2+x3^2+x4^2=5+5/4=25/4