No captions Captions Stop the video above first if it is playing.
No captions Captions Stop the video above first if it is playing.
The students get a feel for how the height above a circular midline changes as they trace their fingers along a circular path. They think about when their height changes quickly and when it changes slowly.
Episode Supports
Students’ Conceptual Challenges
Claire and Mary are asked to describe when the height changes more quickly or more slowly. Initially, they seem to be confused about this question, with Claire interpreting the question as finding steepness and Mary asking for some clarification [1:44].Check in with your students to elicit their ideas about this question, which lays some groundwork for recognizing trigonometric functions as being nonlinear and periodic.
Focus Questions
For use in a classroom, pause the video and ask this question:
[Pause the video at 1:18] Mary and Claire use a hiking analogy to describe the height as they move around the circle. How do you see the height of an object moving along a circular path changing as the angle of rotation changes?
Supporting Dialogue
[Pause the video at 1:44] Tell a partner your ideas about when the height is changing more quickly and more slowly. Be sure to explain your reasoning and connect your ideas to the circle diagram on the screen or on your paper.
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