Now we apply the simplification of fixing the temperature so that the temperature at x@0 and x@2L are equal. This can be achieved with two heat sources.
> restart;
Start with the general equation as always.
> Theta:=x->M*exp(-m*x)+N*exp(m*x);
Set the equations for the endpoints, and equate them to solve for the M and N.
>
eqn1:=Theta[0]=Theta(0);
eqn2:=Theta[0]=Theta(2*L);
> s:=solve({eqn1,eqn2},{M,N});
> assign(s);
>
theta:=simplify(Theta(x)):
Theta:=unapply(theta,x):
This is our general equation with the constants solved for.
> Theta(x);
The temperature at the midpoint.
> Theta(L);
The temperature minimum (@L) can be reduced to a simple equation.
> bookans:=Theta[0]*(2/(exp(-m*L)+exp(m*L)));
> convert(bookans,trig);
> difference:=simplify(Theta(L)-bookans);
Heat Conduction in the Steady State