Khan Academy: Unit Circle: Unit Circle Definition of Trig Functions

You and your learners will enjoy having a nicely organized, typed up unit circle, all filled in with degrees and radians as well as cartesian coordinates. 

Introduce your classes to a new world of mathematics. Pupils learn to call trigonometric ratios by their given names: sine, cosine, and tangent. They find ratios and use known ratios to discover missing sides of similar...

Learners solve and graph 10 different problems that are the inverses of various trig functions. First, they determine which equation is equivalent to a given equation. Then, they find an angle of a right triangle, given its leg lengths....

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.

Sal takes the mystery out of the trigonometric identities by showing how easily they can be derived. He continues with a problem he started in the video �Trig Identities part three (part five if you watch the proofs) and proves the trig...

In this video, Sal reviews the basic trigonometric definitions and identities, including the sum of angle formulas, and then derives the double angle formulas.

SOH, what is this thing called trigonometric ratios? A section of an extensive playlist on geometry identifies the adjacent and opposite sides in relationship of an angle. Using the identified sides, the video defines the sine, cosine,...

Seeing structure in the patterns is key to understanding the unit circle, and it takes time to become comfortable with those relationships. The video gives learners access to repeated instruction to allow time to develop those...

Present examples of trigonometric integrals with a video that shows an example of determining a trigonometric integral. The AP Calculus example shows that many of the trigonometric integrals require manipulation and using trigonometric...

Video about finding the equation of a trigonometric function from its graph. Two examples are sine functions and one example is a cosine function [9:52]