A few comments on LaTeX

LaTeX has been the industry standard in mathematical typesetting for years and, with use on sites sites like Math.SE and other web sites via MathJax, it only becoming more ubiquitous. As a user, you simply type specialized, mathematical markup into your text document and the output as processed by LaTeX is beautiful typeset mathematics. For example, to include something like $f(x)=x^2-x-1 \implies f'(x)=2x-2$ in your page, you just type the following:

  $f(x)=x^2-x-1 \implies f'(x)=2x-2$

The single dollar signs indicate that the expression should be typeset inline. Sometimes, you want the expression to be displayed on it's own and with more spacious spacing, like so: $$\int_{-\infty}^{\infty} e^{-x^2} dx = \frac{\pi^2}{6}$$

In this case, just use double dollar delimiters:

  $$\int_{-\infty}^{\infty} e^{-x^2} dx = \frac{\pi^2}{6}$$

You might notice, by the way, that those statements are both false. The point: LaTeX is a typesetter, not a mathchecker!

To put this all within a document, you might have a look at the first couple of handouts on our main class page. As far as LaTeX implementations go, I'd recommend

Both are free!