This book is for you if you are teaching or studying precalculus. You'll find explanations, interactive diagrams and puzzles to supplement a precalculus curriculum. If any element of this book helps you, use it. Otherwise, pass it on. Part of studying any subject is learning what works for you.

What is precalculus?

Precalculus is all the grunt work of calculus. Calculus is a hugely powerful computational engine. You need to know how to program it. When you solve a problem with calculus, very little of your space will be calculus. Most of your work (and mistakes) will be stuff that is precalculus. If you're really really good at precalculus, your calculus should flow nicely.
That may all sound a little vague and hand-wavy. When the opportunities arise, I'll try to provide examples.

Analytic geometry

We all have an idea of what we think geometry is. Triangles and stuff. Here is how Euclid handled an equilateral triangle oodles of centuries ago. Use the arrow keys to study the step-by-step construction.