f(x)=x^2+1,(x>=0) =1, (x<0)f(x)是一个递增函数,故有:f(1-x^2)>f(2x)1-x^2>2x>=0或者说1-x^2>0,2x<0x^2+2x-1<0(x+1)^2<2-1-根号2=0,故得0<=x<根号2-11-x^2>0,x^2<1,-1综上所述,X的范围是-1 http://zhidao.baidu.com/question/458500498.html