First thing, you will need to be able to project the graphics calculator interface onto a screen, so you will need the calculator's projector screen and a projector, or have the software installed on your laptop and project your laptop.

Then, why not just show them the graph, explain to them that it looks like as you approach the point x = 0 from the left, it approaches the same point from the right.

An alternative (or a supplement) is to use a table and evaluate the function at points closer and closer to x = 0 from both the left and the right. Discuss what it appears the function is tending to.