Introduction to Trigonometric Functions

A handbook of formulas, processes and tricks that summarizes all of trigonometry: special angles, the unit circle, graphs, identities, inverse functions, equations, vectors and polar coordinates. Packed with tables and diagrams, it works as a complete reference.

Earl L. Whitney

A step-by-step guide to the unit circle: angles in standard position, reference angles, and the values of sine, cosine and tangent in every quadrant. Plenty of diagrams make the key ideas easy to see.

Department of Mathematics, University of Houston

A self-study booklet from the University of Sydney on Pythagorean identities, sum and difference formulas and double angle formulas, with a pretest, exercises and full solutions.

Peggy Adamson

A short guide to inverse sine, cosine and tangent that explains why the domain must be restricted and how to solve inverse trig problems with and without a calculator.

Shavana Gonzalez

A focused unit on solving trigonometric equations with special angles, graph symmetries and identities, including examples in degrees and radians and practice exercises.

Mathcentre