@tomleslie , I have another request, how do I use the coefficients of the two approaches (of a*exp(-b*t)-c*t and of the sixth polynomial) in any other further commands; i.e I want to use mf as an explicit function with the numerical coefficients obtained before and the same with the polynomial in further operations.
Here's an example of what I want to do:
PDE2 := diff(u(x, t), t) = diff(u(x, t), x, x)+sin(x+t)-cos(x+t)-(diff(mf, t));
IBC2 := (D(v))(0, t) = 0, (D(v))(1, t) = -0.65e-4*(v(1, t)+mf)^4, v(x, 0) = 1+a
pds2 := pdsolve(PDE2, [IBC2], numeric, time = t, range = 0 .. 1, spacestep = 0.1e-1, timestep = 0.1e-1, errorest = true)*pds2:-plot(x = 1, t = 0 .. 1)
How to make the polynomial and a*exp(-b*t)-c*t with the numerical coefficients available to me?
Thanks in advance.