Maximums occur at the high points when the function is 1 and minimums occur at the low points when the function is $\displaystyle-{1}\usepackage{cmbright}\Huge\$ . On this interval there will be three maximums and two minumums for a total of five. The maximums will occur at $\displaystyle-{2}\pi,{0},\usepackage{cmbright}\Huge\$ and $\displaystyle{2}\pi\usepackage{cmbright}\Huge\$ while the minimums will occur at $\displaystyle-\pi\usepackage{cmbright}\Huge\$ and $\displaystyle\pi\usepackage{cmbright}\Huge\$ .