% 6.4; nonlinear mechanical systems, hard and soft springs, nonlinear pendulum,
 % 6.5; chaos, period doubling, pitchfork bifurcation, York-Li, Feigenbaum. Examples: Duffing, Lorenz, Roessler
\begin{alltt}
 HW 13, due Week 14
 \BF{6.4}: 1, 3, \bx{4}, \bx{8}, 9, 10, 11, 13, 14
 \BF{Computer Lab 4, Resonance}
\end{alltt}
  \href{http://www.math.utah.edu/~gustafso/s2015/2280/2280mapleL4-resonance-S2015.pdf}{http://www.math.utah.edu/~gustafso/s2015/2280/2280mapleL4-resonance-S2015.pdf}