' - - File: XIIIi IVP for first order differential equation: X'{t} = F{t,x}

F{t,x} = -21x + Exp[-t]

to = 0 :  xo = 0 : tf = 5

IVP[F, {to, tf, xo}{1.05,  0.0001}].

' NOTE: Factor of 1.00 --> an "out-of-space" error. Change Factor = 1.05.
'             This example is explained in the Walk Thru documents.

' The TOL = 1E-4 was required for a smooth curve. Try lower TOL to see the outcome.


