Graph; Cursor; Enter Function - Texas Instruments TI-82 Keystroke Manual

40 Calculator Keystroke Guide
cursor to (0,0), and press ENTER. A new Integer graphing window will be produced, this time
centered at the origin. Use the arrow keys to verify that this change has taken place.
page 86

18 Graph

See 16 Window and Default first to learn how to set the left, right, bottom, and top of the
graphing window with the Window settings. To see the graphing window you have selected, press
GRAPH.
page 87

19 Cursor

Press the GRAPH key to display the graphing window. (It doesn't matter which graphing window
you are using, nor does it matter if graphs are displayed.) Press one of the arrow keys. (It doesn't
matter which one.) You will notice that near the center of the screen there is a cross hair, and at
the bottom of the screen there are values for x and y which represent the coordinates of the cross
hair. If you cannot see the cross hair clearly because it lies on one of the axes, press the Up Arrow
key a few times and the Right Arrow key a few times to get the cross hair away from the axes.
You may notice that when you do this, the coordinates displayed at the bottom of the screen
change to reflect the changed position of the cross hair. This cross hair may be moved to any part
of the graphing window by using the arrow keys. The cross hair is sometimes called the general
cursor or free-moving cursor. To turn this general cursor off, just press the GRAPH key.
page 92

20 Enter Function

See also 16 Window and Default and 18 Graph. To graph an equation, to use an expression
repeatedly for computations, or to generate a table of values of an expression (See 22 Table.)
x − , the expression first needs to be entered in the Y= screen. First press the Y= key
such as 2 3
and erase any old expressions by placing the cursor on the expression to be erased and pressing
CLEAR. Then type 2X−3 to the right of the equal sign next to Y
letter X on the screen is to press the X,T,θ,n key. To see the graph of this equation, just press the
GRAPH key. The graph will be displayed on the graphing window with the Window settings you
selected. (Refer to 16 Window and Default.) Using the Standard viewing window, you should see
the graph of a straight line as shown below.
Xmin=-10
Xmax=10
Xscl=1
Ymin=-10
Ymax=10
Yscl=1
You may graph up to ten equations on the same graphing window, using the Y= screen to
define the equations to be graphed. (There are ways to produce more than ten graphs on the
graphing window, but we won't discuss that here.) For example, press the Y= key, keep
Y =2X−3, and move the cursor down to the right of the equal sign for Y
1
. The easiest way to produce the
1
2
and type X . (Use the x
2
2