The first thing that we must do is to select an equation that we want to investigate. Let us start with the exponential function. For Y1, store "Y1=exp^(X)". Turn the plotting option off of Y1. Input Y2 as the anti-derivative. Clear all the other Y function variables. Remember that this is the derivative of the function that we are trying to find.

Let D=DX and N=number of time steps.

:{0}=>L1

:L1=>L2

:Input "X0?", A

:Input "Y0?", B

:Input "DX?", D

:Input "NUMBER OF STEPS?", N

:A=>L1(1)

:B=>L2(1)

:For(I,1,N,1)

:A+D*I=>L1(I+1)

:L2(I)+D*Y1(L1(I))=>L2(I+1)

:End

:PlotsOff

:FnOff

:FnOn 2

:Plot1(Scatter,L1,L2,W)

:ZoomStat

:0=>Ymin

:Equ>String(Y2, Str1)

:Text(1,20, "Y=, Str1)

:Pause

:ClrDraw

:abs((Y2(L1)-L2)/Y2(L1))=>L3

:ZoomStat

:0]Ymin

:Text(1, 25, "RELATIVE ERROR")

:Text(10, 9, MAX ERROR=", round(max(L3), 5))