Study Guide

Trigonometric Functions

Trigonometric Functions Introduction

What is the point of trigonometry? Many have asked, and many are still asking. Some say it's all about angles, and they're right. But trig's true mission in life is to help folks make something out of very little information.

Trig was invented to fill in gaps. How was this done? The math wizards were playing with numbers and triangles, and they had an "aha" moment.

The humble triangle, it turns out, is the building block of most things (as long as they have straight-line boundaries, that is). Take a square, a pentagon, or any other polygon, for example. We can chop up each one of those suckers into triangles.

As an example of trig magic, say we want to find out the distance between a sitting, squawking chicken (A), the coop (B), and a mound of food (C). Join all points, make a triangle, do some trig calculations and, voilà, we now know a lot more about the distance between the three than we did before. Trig won't help explain why that chicken crossed the road, though. Sorry.

Trigonometric Functions Resources


The Math Page: Trigonometry
If you like to hear stories with more than one character's viewpoint, then this math page is for you. It will go over it all again with a different approach.

S.O.S. Math: Solving Trigonometric Equations
All the regular trig stuff, but it also has a really good section on solving trigonometric equations. It's also got some solid practice problems with detailed solutions.

Trigonometry Help
Love jokes? Or history? This site is loaded with trig jokes, trig history, and all the regular trig stuff, too.


Basic Trigonometry
A basic introduction to trigonometric functions: sine, cosine, and tangent. (Not to mention some quality classical tunes.)

Pythagorean Rap
Pythagoras would be proud. You're welcome, world.

You'll find more trig than you can shake a stick at here.

Games and Tools

Trig and Playgrounds
Explore angles in project T.R.I.G. You won't be disappointed.

Games and Trig? Yes, Please.
Calling all crossword puzzle lovers. This is for you.

Fun with the Unit Circle
Around and around we go. Sine, cosine, and tangent are graphed as you rotate around the unit circle. You can see all three at once—in color.