Texas Instruments TI-82 User Manual - Page 21

Displaying and Tracing the Graph

Page 21 highlights

Displaying and Tracing the Graph Now that you have defined the function to be graphed and the WINDOW in which to graph it, you can display and explore the graph. You can trace along a function with TRACE. 1. Press s to graph the selected function in the viewing WINDOW. The graph of Y1=(W-2X)(Là2-X)X is shown in the display. 2. Press ~ once to display the free-moving graph cursor just to the right of the center of the screen. The bottom line of the display shows the X and Y coordinate values for the position of the graph cursor. 3. Use the cursor-keys (|, ~, }, and †) to position the free-moving cursor at the apparent maximum of the function. As you move the cursor, X and Y coordinate values are updated continually with the cursor position. 4. Press r. The TRACE cursor appears on the Y1 function near the middle of the screen. 1 in the upper right corner of the display shows that the cursor is on Y1. As you press | and ~, you trace along Y1, one X dot at a time, evaluating Y1 at each X. Press | and ~ until you are on the maximum Y value. This is the maximum of Y1(X) for the X pixels. (There may be a maximum "in between" pixels.) Getting Started 11

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Getting Started
11
Displaying and Tracing the Graph
Now that you have defined the function to be graphed and the WINDOW in which
to graph it, you can display and explore the graph. You can trace along a function
with TRACE.
1.
Press
s
to graph the selected function in
the viewing
WINDOW
.
The graph of
Y
1
=(W–2X)(L
à
2–X)X
is shown in
the display.
2.
Press
~
once to display the free-moving graph
cursor just to the right of the center of the
screen. The bottom line of the display shows the
X
and
Y
coordinate values for the position of the
graph cursor.
3.
Use the cursor-keys (
|
,
~
,
}
, and
) to
position the free-moving cursor at the apparent
maximum of the function.
As you move the cursor,
X
and
Y
coordinate
values are updated continually with the cursor
position.
4.
Press
r
. The
TRACE
cursor appears on the
Y
1
function near the middle of the screen.
1
in
the upper right corner of the display shows that
the cursor is on
Y
1
. As you press
|
and
~
, you
trace along
Y
1
, one
X
dot at a time, evaluating
Y
1
at each
X
.
Press
|
and
~
until you are on the maximum
Y
value. This is the maximum of
Y
1
(X)
for the
X
pixels. (There may be a maximum “in between”
pixels.)