The function desolve (only tries to solve using Laplace transforms) just isn't up to the task. The two equations you mentioned are solved
by ode2, but ode2 does not solve coupled 1st order DEs. Unless the equations are constant coefficient, I'm guessing that desolve likely will not
solve a system of DEs.
This is pretty unhelpful, I know, but maybe you can try to solve the system somewhat manually using Maxima (one equation that isn't coupled
solve it or convert to a single higher order equation).
--bw
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I am trying to solve a set of coupled 1st order differential equations
which include terms of the type f(y)*y(x) with Maxima 5.26.0:
test: 'diff(y(x),x)+f(x)*y(x)=a;
atvalue(y(x),x=0,1);
desolve(test,y(x));
The result I am getting is:
y(x)=ilt((( laplace( f(x)y(x), x, g1990 )-1) g1990 a)/g1990^2 , g1990, x )
or, in the case of the specific function f(x):=exp(-x^2), a:0:
y(x)= ilt ( ( laplace( exp(-x^2)y(x), x, g2042 ) -1 )/g2042 , g2042, x )
How do I go from here to find the solution?
In the latter case, Mathematica, returns the solution
y(x)=exp( -sqrt(%pi)/2*erf(x) ),
and in the former an expression involving exponentials of
integrals of f(x).
Thanks for your help,
Bertold
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