homework #3 (pdf)
  first-order maple solver (sheet01.mws)
  s2.2.7 integral curve & tangent field (code3Wa.m)
  s2.2.7 integral curves (code3Mc.m)
  problem 2.2.2 solution graphs (code3Ma.m)

  s2.2 (example 1) tangent field (code3Mb.m)
Euler's method online