This list of trigonometric identities includes the factoring formulas near the bottom. A great tool for reference.

This multimedia Learn Alberta math resource looks at how trigonometry is used in making sure that airplanes land safely at airports. The accompanying interactive component gives students practice in using trigonometric ratios, namely...

Twenty problems present a variety of practice working with fundamental trigonometric identities. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the problem then click the "View...

This MathWords.com site lists the equations for all of the trigonometric identities.

This makes for a great handout for learners and teachers, alike! A comprehensive list of 47 commonly-used trig identities.

Faced with a large number of trigonometric identities, students tend to try to memorize them all. This site the emphasis is on understanding how the functions work and on memorizing only about a half dozen of them - all the others work...

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...

Resource provides trigonometry formulas for unit circle, reciprocal identities, ratio identities, Pythagorean identities, sum and difference formulas, and double-angle formulas.

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.

[Free Registration/Login may be required to access all resource tools.] Simplifying trigonometric expressions using identities

[Free Registration/Login may be required to access all resource tools.] This lesson uses trigonometric identities to prove other identities.

[Free Registration/Login may be required to access all resource tools.] Illustrates identities found from dividing two trigonometric functions.

[Free Registration/Login may be required to access all resource tools.] This concept teaches students to solve word problems using trigonometric ratios.

[Free Registration/Login may be required to access all resource tools.] This concept teaches students to use inverse trigonometric ratios to solve for missing angles in right triangles.

[Free Registration/Login may be required to access all resource tools.] Simplify trigonometric expressions using identities.

[Free Registration/Login may be required to access all resource tools.] Use a calculator to find trigonometric ratios.

[Free Registration/Login may be required to access all resource tools.] This concept teaches students to find trigonometric ratios with a calculator in order to find missing sides of right triangles.

Students explore trigonometry concepts through this collection of definitions, lessons, examples problem-solving steps and strategies, and practice problems. Topics include solving triangles, trigonometric functions, theorems, and the...

Students will define basic terms relating to trigonometry and use trigonometric ratios.

This activity has the teacher to create 3 triangles on Cabri Jr. on the TI-83 or TI-84. It will prove to students how trigonometry ratios are found. It will show to the students where the ratios are derived rather than just telling the...

Students show comprehension of advanced mathematical concepts in Trigonometry. The online quiz assesses the scholars on basic trigonometric identities.

A collection of lessons and practice exercises on trigonometric ratios. Students will learn how to solve for an angle and for a side, and to apply trigonometry in setting up and solving word problems.

Excellent site reviewing the realms of Trigonometry. Topics Include the trig functions, graphs, right triangles and much more.

The Northeast Parallel Architectures Center, Syracuse University, provides a review and tutorial site on trigonometry. The information is in-depth and can be accessed by clicking on the various links in the outline.