Three dimensional graphs on your TI-89

In Calculus we are asked to consider three dimensional graphs.  Most students have not had experience graphing or visualizing three dimensional graphs.  The TI-89 can help us visualize three dimensional graphs.  

The three dimensional graphs are described in several ways. But they usually begin by describing a two-dimensional surface and generate the third dimension from that surface by either slicing perpendicular to that region or rotating that region.

Based upon an article by Lin McMullin (Visualizing Solid Figures (Technology Tips) in the May 2001 Mathematics Teacher)

Known cross-section (Squares)

Known cross-section (Equilateral Triangles)

Rotation about the x-axis