This threepart example illustrates the use of iteration, recursion, and algebra to model and analyze the changing amount of medicine in an athlete's body. This example is adapted from High School Mathematics at Work, a publication from the National Research Council (1998, p. 80). These activities allow high school students to study modeling in greater depth, as described in the Algebra Standard.
Through multiple representations of a common concept, better insight into, and a deeper understanding of, the problem situation can be achieved.
The following links to an updated version of the eexample

Using Graphs,
Equations, and Tables to investigate Iteration and Recursion (applet)
In this eexample, students are able to iterate up to 100
times after defining their own initial value and recursive function.

The eexample below contains the original applet which conforms more closely to the pointers in the book.

Modeling the Situation (7.2.1)
An interactive environment is used to become familiar with the parameters involved and the range of results that can be obtained. 

LongTerm Effect (7.2.2)
The interactive environment is used to investigate how changing parameter values affects the stabilization level of medicine in the body.


Graphing the Situation (7.2.3)
An interactive graphical analysis provides a visual interpretation of the results.
