Education Technology

Application of the Unit Circle

Published on 07/01/2010

Activity Overview

Students will use the unit circle and its relationship to the sine and cosine functions to solve a real-world application. Students will find the position of teeth around a 2-inch-diameter cogwheel using ordered pairs at specified degrees around the circle.

Key Steps

  • Image

    The diagram on page 1.6 shows the relationship between the unit circle and the sine function. The sine function can be used to represent the y-coordinate of point P for each angle. Students should notice that the highlighted leg in the triangles created in the unit circle is vertical.