Texas Instruments PLUS TI-89 - Manual (Page 173)

156 Chapter 10: 3D Graphing
10_3D.DOC TI-89/TI-92 Plus: 3D Graphing (English) Susan Gullord Revised: 02/23/01 11:00 AM Printed: 02/23/01 4:22 PM Page 156 of 22 10_3D.DOC TI-89/TI-92 Plus: 3D Graphing (English) Susan Gullord Revised: 02/23/01 11:00 AM Printed: 02/23/01 4:22 PM Page 156 of 22
From the Graph screen, you can:
¦ Trace the equation.
¦ Use the „ Zoom toolbar menu to zoom in or out on a portion of
the graph. Some of the menu items are dimmed because they are
not available for 3D graphs.
¦ Use the ‡ Math toolbar menu to evaluate the equation at a
specified point. Only 1:Value is available for 3D graphs.
Overview of Steps in Graphing 3D Equations
To graph 3D equations, use the same general steps used for
y(x) functions as described in Chapter 6: Basic Function
Graphing. Any differences that apply to 3D equations are
described on the following pages.
Graphing 3D
Equations
Exploring the Graph
Tip: You can also evaluate
z(x,y) while tracing. Type
the x value and press
¸ ; then type the y value
and press ¸ .
Set Graph mode ( 3 )
to 3D.
Also set Angle mode,
if necessary.
Define 3D equations on
Y= Editor ( ¥ # ).
Select ( † ) which
equation to graph. You
can select only one 3D
equation.
Define the viewing cube
( ¥ $ ).
Change the graph
format, if necessary.
ƒ 9
— or —
TI - 89: ¥ Í
TI-92 Plus: ¥ F
Graph the selected
equation ( ¥ % ).
Tip: To help you see the
orientation of 3D graphs,
turn on Axes and Labels.
Note: Before displaying the
graph, the screen shows
the “percent evaluated.”
Tip: To turn off any stat
data plots (Chapter 16),
press
‡ 5 or use † to
deselect them.
Note: For 3D graphs, the
viewing window is called
the viewing cube.
„ Zoom
also changes the viewing
cube.