Describe each of the following properties of the graph of the cosine function, f(theta) = cos(theta), and relate the property to the unit circle definition of cosine.
Amplitude
Period
Domain
Range
x-intercepts
I know the definitions and descriptions, I just need to know how it relates to the unit circle
Amplitude: the height of the graph from the peak to the axis. On the unit circle it would be the radius (max and min values) at 0, pi/2, 2pi Period: the length of one full cycle of the cos graph. On the unit circle it is the circumference. The distance around a circle with radius = 1. Domain: the x value or the values on the horizontal axis. On the unit circle these would be the radian measures around the unit circle such as pi/6, pi/4, pi/3, pi/2. Range: the y value or the values on the vertical axis. On the unit circle it would be the cosine value for each radian measure. Such as cos pi/4 = (sqrt2)/2, cos pi/3= 1/2. X-intercepts: the points where the graph crosses the horizontal axis. On the unit circle these are the cosine values when theta is at the vertical points of the unit circle, pi/2 and 3pi/2.
