Subtracting 3 on the inside of the radical moves the graph to the right from the graph of $\displaystyle\sqrt{{x}}\usepackage{cmbright}\Huge\$ . The graph of $\displaystyle{f{{\left({x}\right)}}}\usepackage{cmbright}\Huge\$ will begin at $\displaystyle{\left({3},{0}\right)}\usepackage{cmbright}\Huge\$ and increase, as does this graph. Check further by evaluating the function for different inputs. The graph must pass through $\displaystyle{\left({4},{1}\right)}\usepackage{cmbright}\Huge\$ , $\displaystyle{\left({7},{2}\right)}\usepackage{cmbright}\Huge\$ , and $\displaystyle{\left({12},{3}\right)}\usepackage{cmbright}\Huge\$ , and it does.