solve() does not gives me all solutions of a system of 5 variables

Question

David Demory 2021-4-16

回答： Vishesh 2023-9-22

Hi all,

I have an ODE model of 5 equations:

dXi/dt = f(Xi,dt) with i = 1 to 5.

I integrated it using numerical solver like ode45 and obtain an equilibrium with the 5 variables Xi* > 0 in |R.

I try to solve it for dXi/dt = 0 using the function solve to find the symbolic values of Xi*.

The solve function gives me only 4 solutions but does not gives me the one that have the 5 variables at equilibrium ...

Do you know why and how to solve it?

Thansk a lot,

Best,

D.

Answer 1

Vishesh 2023-9-22

I understand that "solve()" function is not giving solution for one of your equations.

I would like to inform you that "solve()" function returns empty matrices when no solutions exist for the given equations.

To resolve this issue, please double-check your equations and run your code again.

For more information on "solve()" function, please refer to the following documentation:Equations and systems solver - MATLAB solve - MathWorks India