Tracing A Function - Texas Instruments TI-89 Manual Book

Tracing a Function

Beginning a Trace
Note: If any stat plots are
graphed (Chapter 16), the
trace cursor appears on the
lowest-numbered stat plot.
Moving along a
Function
Note: If you enter an x
value, it must be between
xmin and xmax.
Tip: If your screen does not
show coordinates, set the
graph format so that
Coordinates = RECT or
. Press:
POLAR
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Tip: Use QuickCenter,
described on the next page,
to trace a function that goes
above or below the window.
To display the exact coordinates of any plotted point on a
graphed function, use the ... Trace tool. Unlike the free-
moving cursor, the trace cursor moves only along a function's
plotted points.
From the Graph screen, press ....
The trace cursor appears on the function, at the middle
the screen. The cursor's coordinates are displayed at the bottom of
the screen.
If multiple functions are graphed, the trace cursor appears on the
lowest-numbered function selected in the Y= Editor. The function
number is shown in the upper right part of the screen.
To move the trace cursor:
To the previous or next plotted point
Approximately 5 plotted points
(it may be more or less than 5,
depending on the
xres
To a specified x value on the function
The trace cursor moves only from plotted point to plotted point
along the function, not from pixel to pixel.
Trace coordinates are
those of the function, not
the pixel.
Each displayed value is calculated from the
y
If the function is undefined at an
You can continue to trace a function that goes above or below the
viewing window. You cannot see the cursor as it moves in that
"off the screen" area, but the displayed coordinate values show its
correct coordinates.
Do this:
Press A or B.
Press 2 A or 2 B.
Window variable)
Type the
press ¸.
Function number being
traced. For example: y3(x).
value, the
x
Chapter 6: Basic Function Graphing
x value on
x value and
value; that is, =
x y y n (x)
value is blank.
y
117
.