Graphing Calculator: Graphing Inequality Functions (12/94)


My customer is a university math professor who uses the Graphing Calculator through an overhead projector in his classroom of 400+ students.

The Graphing Calculator appears not to accept the "less than or equal to" (▓) or "greater than or equal to" (│) operators. If you press option-< or option->, nothing appears in the equation box. He wants to graph inequalities beyond "y > x + 2" and enter something like "y ▓ 4 x". Graphing Calculator help says it can graph inequalities and simple algebra.

Is support for the ▓ and the │ hidden from the user or unavailable altogether? What other operators are unavailable?

Here is the answer I received from Engineering:

Graphing Calculator can graph functions of x, functions of x and y, and inequalities. The ▓ and │ characters denote equalities. Therefore, the ▓ and │ characters are unavailable altogether in Graphing Calculator.

There are ways to graph inequalities. For example, you cannot graph x = y, but you can graph |x - y| < 0, which is the same thing. To do this, you must turn on Honest 2D Plotting.

Engineering stated that if an operator is not in the Graphing Calculator help screen (accessible from the Balloon Help menu), then Graphing Calculator cannot do it. Graphing Calculator was included with the Power Macintosh to show the potential of the PowerPC chip and no Apple resources are currently allocated for development of a future version.


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Published Date: Feb 19, 2012