% 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{6.5}: Not covered in class, nothing due.
 \BF{Computer Lab 5, Brine Tank, Due by May 7}:
 \end{alltt}
\vspace{-1pc}
 \href{http://www.math.utah.edu/~gustafso/s2019/2280/maple/lab5/2280mapleL5-brineTank-S2019.pdf}{\footnotesize\url{http://www.math.utah.edu/~gustafso/s2019/2280/maple/lab5/2280mapleL5-brineTank-S2019.pdf}}