Math Medics
S.o.s. Math: Table of Trigonometric Identities
This tutorial highlights the numerous trigonometric identites (but does not define the basic trigonometric functions).
Analyze Math
Analyze Math: Trigonometry: Sum and Difference Formulas Examples
The mathematics tutorial examines trigonometric formulas. The tutorial consists of examples with solutions. The tutorial demonstrates how to use sum and difference formulas to solve problems in trigonometry.
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.