Texas Instruments TI-82 Keystroke Manual page 20

any one of the ten y's in the Y= screen), store the desired value in X, and ask for the value of the
variable Y . How to do all of this is perhaps explained better by looking at the following example.
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On the Y= screen enter
Home screen. To get the value of this y when x is −6, store −6 in X (see 14 Store) by pressing −6
STO > X and then ENTER. Now all you need to do is ask the calculator for the value of Y
this, first press 2nd [Y-VARS]. Next press ENTER to choose the Function... menu. Choose Y
this menu by pressing 1 (or ENTER, since Y
Y-VARS menu
The calculator returns to the Home screen, and the variable Y
screen. Press ENTER to find the value of Y
−2. (Check the result with pencil and paper.) To find the value of Y
display the variable Y
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instead of going through VARS again.), and press ENTER. Try this same approach to find the
value of Y when x is 0, 2, and 5. The answers may be found in Example 1 on page 93 of your
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text.
On the TI-82 there are other ways to evaluate an expression. One way relates the results to
the graph. Graph the equation
(Zoom 6).
Press 2nd [CALC] to display the Calculate menu. Press 1 or ENTER to choose the value
command. The Graph screen is displayed, and at the bottom of the screen appears Eval X=,
followed by a cursor. Type in the value of x you want, such as −6 in the example above. When
you press ENTER, the coordinates of the point on the graph where x = −6 appear at the bottom of
the screen: X=-6 Y=-2, and a cross cursor appears on the graph to indicate where that point is.
If you have more than one graph drawn, press the Down Arrow key to see the values of y for the
other equations at the given value of x. See 22 Table for still another way to evaluate a Y variable
for any desired values of x.
= x +
y 4 as Y , that is, Y
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's number is already highlighted).
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when x = −6. The calculator should display the value
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(Try pressing 2nd [ENTRY] a couple times to bring Y
= x +
y 4 mentioned above, using the Standard viewing window
=X+4. Press 2nd [QUIT] to return to the
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Function... menu
will be displayed on the
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when x = −4, store −4 in X,
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back on the screen
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TI-82 15
. To do
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from
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