Click here to purchase the entire book in PDF format. Intuitive Calculus Warning! This chapter is not intended to teach you how to ``do'' calculus. It's just here to give you an intuitive feel for what's being calculated when you see a nasty-looking equation. If you want to learn calculus, this is probably not going to help you at all... Calculus can be thought of as math that can cope with the idea of infinity. In normal, everyday math, we generally stick with finite numbers because they're easier to deal with. Whenever a problem starts to use infinity, we just bail out and say something like ``that's undefined'' or ``you can't do that.'' For example, let's think about division for a moment. If you take the equation $y = \frac{1}{x}$, then you know that, the smaller $x$ gets, the bigger $y$ becomes. The problem is that, as $x$ approaches 0, $y$ approaches infinity which makes people nervous. Consequently, if $x=0$, then we just back away and say ``you can't divide by zero'' and your calculator gives you a little complaint like ``ERROR.'' Calculus lets us cope with this minor problem.