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A simple ordinary differential equation

  • To: mathgroup at smc.vnet.net
  • Subject: [mg98201] A simple ordinary differential equation
  • From: "I. Shechtman" <shechtma at netvision.net.il>
  • Date: Thu, 2 Apr 2009 04:48:09 -0500 (EST)

What is wrong with this equation?

Clear[sol]
f[x_?NumericQ] = 1 - 1111*x'^2;
sol = NDSolve[{x''[t] + (16/10^4)x'[t]^2*Sqr[
f[x[t]]]/x[
    t]^2 - (1458/10^9)*f[x[t]]/x[t]^2 == 
            0, x[0] == 1, x'[0] == 0}, x[t], {
              t, 0, 100}, AccuracyGoal -> 8,
                     PrecisionGoal -> 8, WorkingPrecision -> 
                  30, MaxSteps -> Infinity];
Plot[Evaluate[x'[t] /. sol], {t, 0, 100}]


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