It's easy to find interactive graphing calculators websites, but finding a free, easy to use graphing calculator applet that's not buggy is more of a challenge. One of the best is hosted at Utah State University's NLVM site, the National Library of Virtual Manipulatives. If you're not familiar with it, NLVM is an extensive collection of interactive applets for students and teachers. You'll find not shortage of interesting puzzles and games there, but this time we wanted to highlight their "grapher" applet.
What sets apart the NLVM grapher is its simple to use, yet powerful interface. An easy to use menu at the top of the screen allows for fractions, exponents, square roots, and absolute values, and they can all be inputted just as they appear in a textbook. There's very little clutter on the screen to intimidate users.
There are surprisingly powerful options for a Java based calculator. Of course, there is a simple trace feature, which utilizes a slider bar. There are three additional tabs for users to choose from, parameters, window, and functions.
Parameters allows the user to insert up to three parameters into the equation that can be manipulated with a slider bar. If you are interested in examining translations, this is a very powerful feature since the graph adjusts in real time.
Not surprisingly, the window tab give the user the option to adjust the graph view. Fortunately, it is also possible to zoom by simply using the mouse to select a region to view.
The functions tab gives the user the ability to input up to three functions. One of the really nice features here is that composite functions are supported (although inverse functions are not). Other advanced features offer the ability to choose each functions color and restrict domains.
The applet doesn't contain all the functionality of a high end graphing calculator handheld, but that's not really the point. Whether you're a student using it to try out graphing for the first time or a teacher incorporating it into your lesson, it's a simple and reliable solution. NLVM's grapher is one of the best online graphing calculators available today.
