y=2x+1
2x=y-1
x=(y-1)/2
所以y=2x+1的反函数是 y=(x-1)/2
y=x+1/x-2
xy-2y=x+1
xy-x=2y+1
x(y-1)=2y+1
x=2y+1/y-1
所以
y=x+1/x-2的反函数是y=2x+1/x-1x1