On Sat, Nov 21, 2020 at 7:09 PM <pedroso620@gmail.com> wrote:
I want an analytic solution. I’d like Octave’s answer for
was
. Using symbolic solver for ODEs, the result/answer I get it is shown below.
I don’t know how to solve it.
Please always copy in the main help list so everyone can help and so that the community can learn from our messages. Also, please write your response below the previous message when responding to this list, and whenever possible, please copy in the output of the command line instead of posting a screenshot.
It's helpful to read the documentation for diff and for dsolve.
diff(S,S) is not a differential, it is dS/dS=1. You can see this in your code; no term such as dS appears.
If you know the answer, why are you asking Octave to solve it? These integrals can be done analytically by realizing that d/dx ( ln( f(x) ) ) = df/dx / f(x) . I would recommend posting mathematical questions on math.stackexchange.com/, or consulting the thermodynamics textbook where you found this equation.