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[✓] Solve a differential algebraic equation?

Posted 6 months ago
5 Replies
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I'm trying to obtain a solution to the differential equation as a function, however I keep getting $Failed in return. I'd greatly appreciate if someone could point out what I'm doing wrong and how I can correct this while maintaining the original flexibility of it being a function. Below is the attached .nb file I'm working with. Thank you for your time and consideration.

5 Replies




I was writing my response while you posted yours. I like yours better. But why do we obtain different plots???


Hi David.

A small mistake occurred in my differential equations,I corrected, and now solution is the same as yours.

Regards Mariusz.

Look more carefully at the documentation on NDSolve. With NDSolve you get replacement rules which need to be used to access the solution. With NDSolveValue you get the solutions. The attached notebook gives both approaches. Also, it is best to not begin user variables with capitals since they can conflict with reserved names.

Kind regards,


Ahh, my mistake was so simple, I should slap myself. Thank you, I spent a few hours looking over this thing trying to figure out my error just to simply find out (because of the .nb file that was provided) that instead of putting {X[t], Y[t]} I was putting {X,Y} so it was reading it incorrectly, again, thank you for your time! I appreciate it :3

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