y=根号下tgx^2-3x+1/x^2-1求D？请写出具体步骤，谢谢

来源：百度知道 编辑：UC知道 时间：2024/05/09 18:02:47
tg 写错了，是lg
lg*x^2-3x+1/x^2-1

lg(x^2-3x+1)/(x^2-1)>=0
(x^2-3x+1)/(x^2-1)>0
则(x^2-3x+1)/(x^2-1) 〉=1且x^2-1≠0
(x^2-3x+1)/(x^2-1) 〉=1
(x^2-3x+1)/(x^2-1) -1〉=0
(x^2-3x+1-x^2+1)/(x^2-1)>=0
(2-3x)/(x^2-1)>=0
(3x-2)/(x^2-1)<=0
(3x-2)*(x^2-1)<=0
若3x-2>=0,x^2-1<0
则x>=2/3,-1<x<1
2/3<=x<1
若3x-2<=0,x^2-1>0
则x<=2/3,x>1,x<-1
x<-1

所以x<-1,2/3<=x<1

D在问题中没有出现呀