Graph y=(x^2-9)/(x-3)

Question

Zoom in on the graph around x=3. Give the viewing window when you first see the empty pixel at x=3 or you notice the graph getting "jagged" around there.

I'm using a TI-89, and I've been changing the window and zooming in to try and see the empty pixel, but no luck. I don't see anything. Help, anyone?

Thanks!

bobpursley · Answer

What you see is a function of the programming of particular calculators.

See this:
http://www.coolmath.com/graphit/

type in the function in the function window.

set graph xmin 2.5 x max 3.5 ymin 2 ymax10

hit eval.

Then vary xmin and xmax

I am not certain of the point in this, because what you see is not a function of math, but what a particular calculator does with denominators and how it computes functions with possible zeroes.