Lawrence Hall of Science
The Math Page: Trigonometry: Analytic Trigonometry the Unit Circle
Here is a site that clearly and thoroughly explains the unit circle and all six trigonometric functions of all quadrantal angles. There are example problems solved, problems for the student to attempt, and answers to the student...
Lawrence Hall of Science
The Math Page: Trigonometry: Trigonometric Functions of Any Angle
Here is a site that clearly and thoroughly explains the trigonometric functions of any angle and the polar coordinate system. There are example problems solved, problems for the student to attempt, and answers to the student problems....
Interactive Mathematics
Interactive Mathematics: Sine, Cosine, Tan & Reciprocals
The definitions of the six trig ratios are presented here, along with several examples of how to determine the ratios given 2 or more sides of a right triangle.
Interactive Mathematics
Interactive Mathematics: Trigonometric Functions
Just about everything you need to know about trigonometry can be found here. Interactive examples and demonstrations help to enhance the lessons. Although not required, the tutorial uses Live Math and Scientific Notebook.