\documentclass[12pt]{article}
\usepackage{graphicx,fullpage}

\begin{document}

\section{Three Ways to Display an Equation}

There are several ways to display an equation.  They are equivalent- they
are shown here so that you'll recognize them when they come up.

Double dollar sign: \verb+$$...$$+
$$
x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}
$$

Begin and end an equation environment (this numbers the equation):
\begin{equation}
x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}
\end{equation}

Brackets: \verb+\[ ... \]+
\[
x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}
\]



\section{Figures: Create, Label and Reference}

Have the figure file in the same folder as the tex file.  For this
example, download the figure \verb+clown.jpg+ from the class website.

\subsubsection{Very Basic Example:}
\label{figsection}

\includegraphics[width=2.0in]{clown}

We'll always incorporate a figure into a figure environment, that allows
for captioning, labelling, referencing.  Here is an example:


\begin{figure}[h]
\centering
\includegraphics[width=3.0in]{clown}
\caption{The photo of a famous clown.}
\label{AFace}
\end{figure}

Back in the text, we can now reference the figure (see Figure 
\ref{AFace}).


\section{Label and reference an equation}


Here's the equation:

\begin{equation}
\label{LabelName1}
x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}
\end{equation}

In the text, if I now want to refer to the 
formula (see Equation \ref{LabelName1}).


\subsection{Example: Label and reference a section}

\section{Formulas}
\label{Label2}

In the text, now refer to back (see, for example, 
Section \ref{Label2}).  This is a reference
back to Section \ref{figsection}.


\end{document}
