## Precalculus (6th Edition) Blitzer

The statement is false. The correct statement is, “If $f\left( x \right)=3x$, then ${{f}^{-1}}\left( x \right)=\frac{x}{3}$.”
Let us consider the function below: $f\left( x \right)=3x$ The inverse of $f\left( x \right)$ can be found as follows: $y=3x$ Now interchange y with x $x=3y$ So, $y=\frac{x}{3}$ Thus, ${{f}^{-1}}\left( x \right)=\frac{x}{3}$ is the inverse of f and the above statement is false.