Chapter 1 B-23
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To graph data on the TI-86:
The TI-86 has a built-in command to graph data and autoscale the data window.
Press 2nd + (STAT) F3 (PLOT) to display the STAT
PLOTS screen. (Your screen may not look exactly like
this one.)
Note: When drawing a graph from the y(x)= list, you
may get an error message or see a scatter plot of ÒoldÓ
data as well as the function graph. If so, turn off the
STAT PLOTS with F5 (PlOff) ENTER .
On the STAT PLOTS screen, press F1 (PLOT1) to dis-
play the Plot1 screen, press ENTER to turn Plot1 “On”,
press F1 (SCAT) . Press the menu key under
list L1. Press and the menu key under list L2.
Press and press the menu key corresponding to the
mark. You can choose any of the three marks at the
bottom of the screen.
You can enter the names of any
lists. However, it is easiest to
always work with L1 and
L2.
Press EXIT until you return to the home screen. Go to
the graph menu and clear the y(x)= list . To have the
TI-86 set an autoscaled view of the data and draw the
scatter plot, press GRAPH F3 (ZOOM) MORE F5 (ZDATA) .
(ZDATA does not reset the x and y-axis tick marks.
You should do this manually with RANGE or WIND
if you want different spacing between the marks.)
You can trace the scatter
plot with the TRACE key.
Press GRAPH and access the function list. Notice that
ÒPlot1” at the top of the screen is now dark. This is
because you have turned Plot1 ÒonÓ. If you always put
input data in list L1 and output data in list L2, you can
turn the scatter plot off and on from the y(x)= screen
rather than the stat plots screen from this point on.
To turn Plot1 off, use to move the cursor to the Plot1
position, and press ENTER . Reverse the process to turn
Plot1 back on.
A scatter plot is turned on when
its name on the y(x)=
screen is
darkened. Remember that you
will have lower-case functions.
¥ TI-86 lists can be named and stored in the calculatorÕs memory for later recall and use. I f
you do this and use the list by its stored name, you must use the name of the list in the stat
plot setup or on the stat plot screen each time you change lists. Refer to your TI-86
Guidebook for details.
1.4.6 FINDING FIRST DIFFERENCES When the input values are evenly spaced, use
program DIFF to compute first differences in the output values. If the data are perfectly
linear (i.e., every data point falls on the graph of the line), the first differences in the
