Use the mouse to drag "beads" along a graph and observe what happens to the secant line as they come together.

This was written in JAVA, but even if you don't have JAVA installed you can just click below to
[ Run the Applet using JavaScript&HTML5 via WebSwing] 
Note:  This option does not require any plugin and should work on smartphones as well as computers.
If you do have Java installed and supported by your browser (or if you have installed the cheerpj plugin for display of Java applets using javascript&HTML5), then you can also [Run the Applet using JAVA] 
Note:  Many browsers no longer support Java directly but if you want to see how the applet looks in Java, then one option is to use Internet Explorer or another browser like Chrome with the IETab plugin
Or you can just use this link to
[Download the App] and run it outside your browser.


Note to Students and Teachers:
This applet illustrates how the definition of the derivative of a function actually determines the slope of a tangent line.

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About the GeX library


Copyright 1997,2004 by Alan Cooper - page last modified on 26 Oct2004