Correct. The amplitude is 4. This tells you that the y-coordinate of the low point is $\displaystyle-{4}\usepackage{cmbright}\Huge\$ . Because the coefficient 4 is positive, the graph has the same orientation as $\displaystyle{y}={\cos{{x}}}\usepackage{cmbright}\Huge\$ .

The period of this function is $\displaystyle\frac{{{2}\pi}}{\pi}={2}\usepackage{cmbright}\Huge\$ . Therefore, each hill and each valley will extend over an interval of length 1 (half of a cycle). One hill will have the y-axis running through the middle and will lie on the interval $\displaystyle{\left[-\frac{{1}}{{2}},\frac{{1}}{{2}}\right]}\usepackage{cmbright}\Huge\$ . Next to it is a valley on $\displaystyle{\left[\frac{{1}}{{2}},\frac{{3}}{{2}}\right]}\usepackage{cmbright}\Huge\$ , and then a hill on $\displaystyle{\left[\frac{{3}}{{2}},\frac{{5}}{{2}}\right]}\usepackage{cmbright}\Huge\$ . The low point is in the middle of the valley, so the x-coordinate is 1.