Radiation equation- explicit Euler Method analytical Euler RKfixed.xmcd

I'm teaching a numerical methods course using Mathcad.  This is just file showing several ways to solve the Radiation equation.  Trying to get students into Mathcad programming.  Most of my Civil engineering students have never written code of any kind.  The next step is to have them write a Mathcad program that employs the Euler method.