Incorrect. If $\displaystyle{y}={\left({2}\right)}{{3}}^{{x}}\usepackage{cmbright}\Huge\$ , then $\displaystyle{y}={6}\usepackage{cmbright}\Huge\$ when $\displaystyle{x}={1}\usepackage{cmbright}\Huge\$ but $\displaystyle{y}={18}\usepackage{cmbright}\Huge\$ when $\displaystyle{x}={2}\usepackage{cmbright}\Huge\$ , so this function does not work.