The graph shown is the graph of $\displaystyle{y}={\cos{\theta}}\usepackage{cmbright}\Huge\$ . This graph has a pattern that repeats every $\displaystyle{2}\pi\usepackage{cmbright}\Huge\$ units, so if you were to shift it to the right or left by $\displaystyle{2}\pi\usepackage{cmbright}\Huge\$ units you would get back the same graph. However, if you were to shift it to the right by $\displaystyle\frac{{{3}\pi}}{{2}}\usepackage{cmbright}\Huge\$ units, the new graph would have a valley to the right of the y-axis. This would not match the graph shown.