Texas Instruments PLUS TI-89 - Manual (Page 130)

Chapter 6: Basic Function Graphing 113
06BASFUN.DOC TI-89/TI-92 Plus: Basic Function Graphing (English) Susan Gullord Revised: 02/23/01 4:09 PM Printed: 02/23/01 4:18 PM Page 113 of 22
Press ¥ $ or O 3 to display the Window Editor.
Window Variables
(shown in Window Editor)
Corresponding Viewing Window
(shown on Graph screen)
Variable Description
xmin , xmax ,
ymin , ymax
Boundaries of the viewing window.
xscl , yscl Distance between tick marks on the x and y axes.
xres Sets pixel resolution (1 through 10) for function graphs.
The default is 2.
¦ At 1, functions are evaluated and graphed at each
pixel along the x axis.
¦ At 10, functions are evaluated and graphed at every
10th pixel along the x axis.
From the Window Editor:
1. Move the cursor to highlight the value you want to change.
2. Do any of the following:
¦ Type a value or an expression. The old value is erased when
you begin typing.
— or —
¦ Press M to clear the old value; then type the new one.
— or —
¦ Press A or B to remove the highlighting; then edit the value.
Values are stored as you type them; you do not need to press ¸.
¸ simply moves the cursor to the next Window variable.
You can also store values directly to the Window variables from the
Home screen or a program. Refer to “Storing and Recalling Variable
Values” in Chapter 2.
Defining the Viewing Window
The viewing window represents the portion of the coordinate
plane displayed on the Graph screen. By setting Window
variables, you can define the viewing window’s boundaries
and other attributes. Function graphs, parametric graphs, etc.,
have their own independent set of Window variables.
Displaying Window
Variables in the
Window Editor
Tip: To turn off tick marks,
set xscl=0 and/or yscl=0.
Tip: Small values of xres
improve the graph’s
resolution but may reduce
the graphing speed.
Changing the
Values
Note: If you type an
expression, it is evaluated
when you move the cursor
to a different Window
variable or leave the
Window Editor.
From the Home
Screen or a Program
xmin
ymin
ymax
xmax
xscl
yscl