The Function Visualizer Model displays the graph of a function f(x) with arbitrary parameters. The function can contain polynomial, trigonometric, and exponential expressions as well a parameters. Parameters are connected to sliders that can be adjusted to observe the effect of varying parameter values. This applet was created using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run Java archive. Double clicking the ejs_math_FunctionVisualizer.jar file will run the program if Java is installed. EJS is a part of the Open Source Physics Project and is available in the OSP Collection.