# Division by Zero

A blog about math, puzzles, teaching, and academic technology
Posted by: Dave Richeson | October 28, 2011

## Applet to illustrate the epsilon-delta definition of limit

Here’s a GeoGebra applet that I made for my Real Analysis class. It can be used to explore the definition of limit:

Definition. The limit of $f(x)$ as $x$ approaches $c$ is $L$, or equivalently $\displaystyle \lim_{x\to c}f(x)=L,$ if for any $\varepsilon>0$ there exists $\delta>0$ such that whenever $0<|x-c|<\delta$, it follows that $|f(x)-L|<\varepsilon$.
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