Question

求函數(shù)y=的反函數(shù).

Answer 1

當(dāng)x≥0時(shí),y≥-1,

由y=x²-1,得x= (y≥-1),

故y=x²-1(x≥0)的反函數(shù)是y= (x≥-1);

當(dāng)x<0時(shí),y<-1,

由y=2x-1得x=(y+1)(y<-1),

故y=2x-1(x<0)的反函數(shù)是y=(x+1)(x<-1).

∴f ^-1(x)=