+1(x≥1)的反函数是( )A.y=x2-2x+2(x<1) B.y=x2-2x+2(x≥1)
C.y=x2-2x(x<1) D.y=x2-2x(x≥1)
+1(x≥1)的反函数是( )A.y=x2-2x+2(x<1) B.y=x2-2x+2(x≥1)
C.y=x2-2x(x<1) D.y=x2-2x(x≥1)
B
解析:∵y=+1(x≥1),
∴y≥1.
又∵y=
+1,
∴
=y-1,x-1=(y-1)2,即x=y2-2y+2.
∴所求反函数为y=x2-2x+2(x≥1).