解：设x=lg(y^2-1) (y<-1) x>0 e^x=y^2-1 y=-√(e^x+1)(x>0)
y=lg(x^2-1)10^y=x^2-110^y+1=x^2x=-(10^y+1)^0.5x<-1x^2>1x^2-1>0y∈R反函数y=-(10^x+1)^0.5 x∈R
