# Graphing Applets

As early as 1997 I developed a suite of Java applets for use in calculus
instruction. The main applet was the Grapher (gallery below) and specific calculus
functions were supplied by related variants; the Riemann Sums Grapher and the
Secant Line Grapher.

At the time, graphing calculators such as TI-85 were just beginning to become
staples of calculus instruction at universities, and a couple of years earlier
I had been part of a team tasked with reinvigorating calculus instruction at UNL with
a number of curricular innovations, among which was use of graphing calculators.

Java applets provided the advantage that they could easily be used both in the
classroom and at home or in college labs. The quality of the graphing was
needless to say much higher than the low resolution of calculators at the time
(smart phones wouldn't appear for another ten years!).

The syntax parser in the graphing applets was compatible the the syntax students
were using in their graphing calculators, and also becaome the inspiration
for the intelligent math grading in
WebTests
and Enterprise Diploma.

I used these applets in all my calculus classes from 1997 until the
last class I taught at UNL, in 2010.

## Grapher

Trace the coordinates of a point using crosshairs

Zoom in or out with mouse gestures

## Riemann Sums Grapher

Graph a function and show Riemann sums

Increase the number of strips with a slider

Toggle between left and right sums

## Secant Line Grapher

Graph a function and click to drag out a secant line

Zoom in to approximate by local linearity