Hi Valery,
I had tried it before but was not getting anywhere. I finally was able to find the problem: dT/dx =0 @ 0 does not converge so instead had to change the left boundary of the domain to .000001 instead of 0, that is, dT/dx = 0 @ x = .0000001 instead of 0.
Thanks for the help.
FYI, in Mathcad Prime 3.0 we can find the same solution without anyother problems. Units cannot be used, though.
Regards,
Josué