Each labeled point on the graph at right is either a maximum or a minimum.
Find the period and amplitude of the graph.
Period: How far is it between consecutive maximums or minimums?
Amplitude: How “tall” is the graph? Divide this answer by
Find an equation for the graph.
Find the vertical and horizontal shifts. For the vertical shift, what number is in the middle of
Review the Math Notes box in Lesson 7.2.4 for help with the general equation of a sine or cosine graph.
In this case, it is more convenient to use cosine because you know a maximum point.
Use one of the labeled points to check your equation.
Substitute the values for each of the points into the equation to verify that it is correct.