Khan Academy
Introduction to the Unit Circle, Trigonometry
In this video, Sal shows how the sine and cosine of an angle are defined on the unit circle. He inscribes a 30-60-90 triangle in the unit circle and explains how to use SOH-CAH-TOA to find the circle's coordinates.
Curated OER
What Does the Graph of the Sine Function Look Like?
Using the unit circle and the values of _ at 0, ¹/2, ¹, and 3¹/2, the instructor shows how to construct the sine graph by translating the y-coordinate of the unit circle to the graph. She then looks at the domain, range, amplitude,...
Curated OER
What Does the Graph of the Cosine Function Look Like?
Using the unit circle and the values of _ at 0, ¹/2, ¹, and 3¹/2, the instructor shows how to construct the cosine graph by translating the x-coordinate of the unit circle to the graph. She then looks at the domain, range, amplitude,...