%% ================================================================
\section{Introduction}

for now: exemplars of hamiltonians and lagrangians.
particular coordinates?

\begin{itemize}
\item simple harmonic oscillator
\item circular motion
\item linear motion
\item 3D motion with arbitrary V?
\item electromagnetic
\item what else?
\end{itemize}

action principle: $d\mcL/d\phi_i = 0$ where
$$
	\mcL[\phi_i] = \int L[\phi_i(s)]d^ns.
$$
$L$ is the Lagrangian; $\mcL$ is the action functional.

Why does $L=T-V$ work?

why is the ham the leg xform of the lagr?

%% ----------------------------------------------------------------
bib: wiki article on lagr, lagr mech, ham mech.
