Entering Functions

Entering Functions

The Basics:

Basically, the applet will display the graphs of up to four functions at once. You type a function in one of the input fields beneath the graphing area, and press the <Enter> or <Return> key on your keyboard. If you are used to entering functions in a graphing calculator, entering functions in the graphing applet should pose no problems for you.

entering functions


The applet recognizes only the variables "x" and "y". X is assumed to be the independent variable and is graphed on the horizontal axis, and y is assumed to be the dependent variable and is graphed on the vertical axis.

Arithmetic Operators:

The applet uses the standard arithmetic operators:

Built-In Functions:

The applet supports several elementary functions, including:

Turning Graphs On/Off:

You can use the checkbox to the left of the function to turn the graph of particular functions on and off.

X-Scan & Y-Scan

If X-Scan is checked, the program will sketch curves that are more-or-less vertical pretty well, but will tend to skip a lot of points across lines that are more-or-less horizontal (See "How It Works"). Y-Scan will draw the more-or-less horizontal parts of a curve pretty well, but not the more-or-less vertical parts. You may want to get the viewing rectangle you want, then check both X-Scan and Y-Scan to get the best graph.

This feature has no effect on the graph of an explicit (y = f(x)) function.

Syntax Errors:

If you make a mistake typing your function, the program will ignore the input and display a "syntax error" message in the message area to the right of the graph display. At the moment, this message is not very helpful in identifying your error - I'm working on that.

last update April 14, 2008 by JL Stanbrough