Provides a detailed explanation of trigonometric functions with examples of reference angles and ratios.

An introduction to solving acute and obtuse triangles by using the law of cosines, including a derivation of the formula. Includes several pistures and examples.

[Free Registration/Login may be required to access all resource tools.] Here you'll learn how to solve trigonometric equations using the half angle formulas.

[Free Registration/Login may be required to access all resource tools.] Advanced applications of trigonometric identities.

Here is a site that clearly and thoroughly explains the trigonometry of a right triangle, including finding the values of all six trig functions given a single value. There are example problems solved, problems for the student to...

Given the sine (or cosine) of an angle, find its cosine (or sine) using the Pythagorean identity. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

A comprehensive guide for learning all about the basics of trigonometry, the various identities-formulas of trigonometry, solved examples, and practice questions.

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.

Introduces techniques for solving trigonometric equations. Provides worked examples of solving some simpler to medium-hard equations.