Windstream
Ojk's Precalculus Study Page: Sum and Difference Formulas for Tangent
This tutorial introduces the sum and differnce formulas for tangent, and gives several examples of problems to be solved as well as proving other identities. Assumes knowledge of the sum and difference formulas for sine and cosine.
Math Medics
S.o.s. Math: Trigonometry: The Addition Formulas
This math lesson contains a list of trigonometric addition formulas. Includes example problems involving these formulas along with solutions.
Other
Sierra College: Trigonometric Identities
Provides trigonometric identities, which include fundamental identities, even-odd identities, addition formulas, double-angle formulas, subtraction formulas, product-sum formulas, and identities for sin squared and cos squared.
Wolfram Research
Wolfram Math World: Trigonometric Addition Formulas
This tutorial offers formulas and explanations on trigonometric addition formulas and features an easy way to remember the sine and cosine addition formulas using matrices.
Windstream
Ojk's Precalculus Study Page: Sum and Difference Formulas for Sine and Cosine
An introduction to trigonometric identities, beginning with the sum and difference formulas. Some of the formulas are proven, some are left to the reader. Includes several examples and pictures.
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.
Analyze Math
Analyze Math: Trigonometry: Sum and Difference Formulas
Students explore trigonometric formulas. Definitions of the sum and difference formulas are included.
Free Math Help
Free Math Help: Trigonometry Addition Formulas
Students learn about the trigonometric addition formulas. Sine, cosine, and tangent formulas are included.