Worksheet 9, Clip 1, Discussion of Question 1, Part 1, 4:49

• Initially the students' responses demonstrate they may not completey understand the meaning of period. Notice that the teacher continually refocuses them on period.
• In this discussion, Disney represents the argument of the trig function. During the conversation, one student gives a respons in terms of a circle. The teacher gives credit to this suggestion by the way he responds to this suggestion.
• Making the distinction between the argument of the function and θ is very difficult for students. By taking the time to make this distinction, the teacher can discuss period by having the students consider what θ will vary by.
• This discussion is an example of how difficult this concept is for students. The teacher guides the the students to recognize what the argument of the trig function is versus the input (which sometimes are the same). This helps the students see this as function composition which is a topic they have seen before. By the end of the discussion they realize that the argument always varies by 2π, although there still seems to be some confusion between θ and the argument of the trig function.