# Trigonometric Functions as Projections

These web pages provide a series of interactive lessons to
introduce the concept of trigonometric functions as projections based
on the unit circle. They are not intended to be used instead of a text book,
but as a supplement to give students another way of exploring the
subject material.

These pages make use of JavaScript interactives built with JSXGraph to allow student interaction
with the various graphs presented.

Most pages includes some brief exercises to check your understanding. Answers to the exercises are
provided, and students should check their work before progressing.
Whenever you get an answer incorrect, make sure you take the time to
understand where you went wrong. Incorrect answers can be a great
opportunity to learn if you do this.

Some of the answer pages include
additional teaching points.

## The lessons

- Introduction
- The sine function
- The cosine function
- The tangent function

*Copyright Glen Prideaux, 2003, 2021.*

These pages may be
freely copied for non-commercial use.