In[17]:=

(* The damped harmonic oscillator x'' + (1/5) x ' + x = 0 with intial condition x (0) ... ]  -x[t] - (1/5) * v[t], x[0] 1, v[0] 0}, {x[t], v[t]}, {t, 0, tmax}][[1]]

Out[17]=

{InterpolatingFunction[{{0., 30.}}, <>][t], InterpolatingFunction[{{0., 30.}}, <>][t]}

In[18]:=

TimeStatePlot[Evaluate[soln], {t, 0, tmax}, PlotPoints200, AxesLabel {t, x, v}] ;

[Graphics:HTMLFiles/damped_4.gif]

Created by Mathematica  (March 14, 2006)