m(x^2-1)<2x-1
当x^2>1时,(2x-1)/(x^2-1)>m
要使得不等式恒成立,那么不等式左边要比右边最大值还大,即,(2x-1)/(x^2-1)>=2
求得1当x^2=1,求得x=1时成立
当x^2<1时,(2x-1)/(x^2-1)＜m
要使得不等式恒成立,那么不等式左边要比右边最小值还小,即,(2x-1)/(x^2-1）<=-2
求得（-1+根号7)/2<=x<1
综上（-1+根号7)/2<=x<=(1+根号3)/2