Texas Instruments TI-89 User Manual

3D Graphing

382

Note:

During a trace, you can also evaluate

z(x,y)

. Type the x value and press

¸;

then type the y value and press

¸.

Moving the Cursor in 3D

When you move the cursor along a 3D surface, it may not be obvious why the cursor
moves as it does. 3D graphs have two independent variables (

x,y

) instead of one, and

the x and y axes have a different orientation than other graphing modes.

How to Move the Cursor

On a 3D surface, the cursor always follows along a grid wire.

‡

Math

Only 1:Value is available for 3D graphs. This tool displays
the z value for a specified x and y value.
After selecting 1:Value, type the x value and press

Then type the y value and press

Cursor Key

Moves the cursor to the next grid point in the:

Positive x direction

Negative x direction

Positive y direction

Negative y direction

Tool

For 3D Graphs: