University of Saskatchewan (Canada)
University of Saskatchewan: Trigonometric Identities
The University of Saskatchewan provides an explanation of trigonometric identities, including the reciprocal identities, the addition and subtraction formulas with sine and cosine, and the double angle formulas. There are links to...
Lawrence Hall of Science
The Math Page: Trigonometry: Trigonometric Identities
This resource clearly and thoroughly explains the many types of trigonometric identities. There are example problems solved, problems for the student to attempt, and answers to the student problems.
Analyze Math
Analyze Math: Trigonometric Identities
Learners explore trigonometric identities. Definitions of the Pythagorean, reciprocal, tangent, and negative identities are included.
Math Words
Math words.com: Trig Identities
This MathWords.com site lists the equations for all of the trigonometric identities.
Interactive Mathematics
Interactive Mathematics: Trigonometric Functions
This is a excellent review lesson about trigonometric functions of any angle. Good examples here.
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.
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.