Demonstrates how to evaluate trigonometric functions by using trig identities.

Lists the basic trigonometric identities, and specifies the set of trig identities to keep track of, as being the most useful ones for calculus.

Demonstrates how to translate, set up, and solve basic right-triangle word problems.

Relates the unit circle to the method for finding trig ratios in any of the four quadrants. Demonstrates how the unit circle might be useful.