> I would like to understand the difference between the functions g(x)
> and h(x) defined below. In particular, lines
> (%i3) and (%i6) seem to produce the same output to the screen, but
> give different outputs when $x$ is set to be 2.
They produce the same output with the argument 'x', but not with the
argument '2'. That is because you can differentiate with respect to
'x', but not with respect to '2'.
-s