Abstract/Description:
The transition from the static perspective of right triangle trig ratios to the dynamic perspective of circular trig functions, and from measuring angles in degrees to measuring angles in radians, can generate roadblocks and misconceptions. In this session we will examine a sequence of tasks that reveal, rather than obscure, trigonometric ideas. Participants will engage in tasks that develop the following CCSSM concepts for students: (1) defining radians as a proportionality constant, prior to defining radians as an arc length on a unit circle; (2) using the unit circle to generalize the definitions of the trigonometric functions and to establish trig identities, rather than focusing on memorizing "special angles" which can hinder students' understanding; (3) modeling contexts with trig functions, rather than just sketching graphs.
Presenter:
Scott Hendrickson, Brigham Young University