In these exercises, use the notation for sine and cosine given on page 53 of the textbook in Figure 1.65. This means we should work with a circle of radius 1 and t should represent the angle made by the radius of the circle from O to P and the positive x-axis. We measure t in radians. Then if P = (x,y), we have
The graphs of the functions 
and 
are given in Figure 1.66 on
page 53 of the text.
We will also want to use the definitions of period and amplitude given on page 53.