This could be a graph of $\displaystyle{f{{\left({x}\right)}}}=-{4}+\sqrt{{x}}\usepackage{cmbright}\Huge\$ . When you subtract a number outside the radical, the graph moves down from the graph of $\displaystyle\sqrt{{x}}\usepackage{cmbright}\Huge\$ . When you add a number outside the radical, the graph moves up from the graph of $\displaystyle\sqrt{{x}}\usepackage{cmbright}\Huge\$ .