Question

If $y=f\left(x\right)=\frac{x+2}{x-1}$, then show that $x=f\left(y\right)$.

Answer 1

Let $y=f\left(x\right)=\frac{x+2}{x-1}$

or, $y(x-1)=(x+2)$

or, $x(y-1)=y+2$

or, $x=\frac{y+2}{y-1}$

or, $x=f\left(y\right)$.