QuadraticEquation 2009-02-11 02:30:32 2009-02-11 02:32:07 Definition terms % this is the default PlanetMath preamble. as your knowledge % of TeX increases, you will probably want to edit this, but % it should be fine as is for beginners. % almost certainly you want these \usepackage{amssymb} \usepackage{amsmath} \usepackage{amsfonts} % used for TeXing text within eps files %\usepackage{psfrag} % need this for including graphics (\includegraphics) %\usepackage{graphicx} % for neatly defining theorems and propositions %\usepackage{amsthm} % making logically defined graphics %\usepackage{xypic} % there are many more packages, add them here as you need them % define commands here The quadratic equation \begin{equation} r = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \end{equation} can be used to find the solutions (roots) to a second order polynomial $$ax^2 + bx + c = 0$$