*** Midpoint Rule (freeware)
*** by Daniel J. Bishop
*** danb2k@hotmail.com

Files in this archive:
TRAPRULE.83P -- Midpoint Rule Program
SCREEN.83P -- screenshots of this program
README.TXT -- this file

How to use this program:

1. Run TRAPRULE from the PRGM menu.
2. Enter a function in terms of X.
3. Enter the lower bound for the integration (Xmin).
4. Enter the upper bound for the integration (Xmax).
5. Enter the number of trapezoids to use (N).
6. The calculator now displays a graph of the function plus the trapezoids used in the trapezoidal rule approximation.  Press ENTER to continue.
7. The calculator will now display the estimate of the integral using the trapezoidal rule and the more precise value obtained from the fnInt function.

Screenshots

The integral estimated in these examples is fnInt(normalpdf(X),X,-2,2).

Figure 1: Trapezoidal rule approximation, N=4.
Figure 2: Trapezoidal rule approximation, N=8.