# Question:Nonlinear DE

## Question:Nonlinear DE

Maple

Hi all, I'm not good at maple, so need a help from experts. I'm using Maple v.12. -part of the code- ... de2:= # Nonlinear DE is here # ics:= X(0) = 1, (D(X))(0) = 1; sol:= dsolve({de2, ics}, numeric, method = rkf45); (or sol := dsolve({de2, ics}, x(t), numeric, stiff = true, range = 0 .. 200);) Error, (in f) unable to store '1.0000000024691*{1.}^2+2000010000.' when datatype=float[8] -end of the code- As you see above, It's a simple process to solve DE. so most of the DE, like (1) below, is solved very well through the code. But my case is (2). I could see error msg as you see above. ics(initial condition) and coeff. can be changed. In eq.(2), I made all the coeff. as 1. I thought I could find some tendency of the result, but got returned error. plz let me know what the erroe msg means, and then how to solve and plot my eq. Thanks, (1) (Van der pol oscillator) ode := diff(x(t), t, t)+(1000*(x(t)^2-1))*(diff(x(t), t))+x(t) = 0 (2) ode := diff(X(t), t, t)-{diff(X(t), t)}^2/X(t)-(1+(2*(1+cos(t)))*sin(t)/(1+(1+cos(t))^2)+X(t)/(1+(1+cos(t))^2))*(diff(X(t), t))-(2+(4*(1+cos(t)))*sin(t)/(1+(1+cos(t))^2)-2/(1+(1+cos(t))^2))*X(t)-2*{X(t)}^2/(1+(1+cos(t))^2) = 0

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