The graph of a cosine function is drawn. One full cycle goes from $\displaystyle{x}={0}\usepackage{cmbright}\Huge\$ to $\displaystyle{x}={1}\usepackage{cmbright}\Huge\$ and the low point on that cycle is $\displaystyle{\left(\frac{{1}}{{2}},-{5}\right)}\usepackage{cmbright}\Huge\$ . Which of the following functions could have this graph?