expsin_errors:
  Solve the expsin ODE using rk1, rk2, rk4.
  Use n = 5, 10, 20, 40, 80 steps.

    N        rk1        rk2        rk4

    5      1.401      1.352     0.3275
   10      1.171     0.4286      0.017
   20      0.668    0.08303  0.0005983
   40     0.3765    0.01884  3.051e-05
   80     0.2028   0.004525  1.729e-06