# Tagged Questions

Questions on the symbolic (DSolve, DifferentialRoot) and numerical (NDSolve) solutions of differential equations in Mathematica.

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### NDSolve point animation not working [closed]

The below code plots the path of a ball bouncing but loses 90% of its velocity each time it bounces. (adapted from https://reference.wolfram.com/language/ref/WhenEvent.html). ...
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### I am having trouble with the DSolve function [closed]

DSolve[{x''[t] + 0.01 x'[t] + x[t] == E^(It), x[0] == 1, x'[0] == 1}, x[t], t] This give the following error :"Equation or list of equations expected instead ...
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### How to change the boundary condition near singularity

The following system has a singularity around $x=0.451$. What I want to do is to detect when the solution gets close enough to this singular point (in this example I'm using the threshold of $0.001$), ...
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### DSolve does not give an analytic solution for a tutorial input [closed]

I am just starting with Mathematica and I have tried to solve PDE following DSolve, with first three inputs from the Elliptical Partial Differential equations ...
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### Nonlinear PDE system in a rectangle

This question is posted by two physics students working together. We are having some trouble while trying to solve Navier-Stokes equations, The main problem is that, while our set of partial ...
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### Plotting graphical analysis of chaotic behavior

I am trying to plot some results of chaotic behavior in a system based on a paper for one of my classes. I am a physics undergrad. I found some sample code online springy.nb which I have been trying ...
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### How to omit the corrupt value in a program?

I've such errors: Coordinate .. is not a floating-point number and can't correctly fix it. The problem occures when x==Log[2] The program works correctly ...
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### Change value of constant during NDsolve

So far, I have this: ...
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### Numerical optimal control

I was hoping to tackle optimal control using Mathematica in order to learn how I can use Mathematica's built in numerical integration and optimization functions together in order to solve an optimal ...