user manual

17-4 Applications
8317APPS.DOC TI-83 international English Bob Fedorisko Revised: 02/19/01 1:00 PM Printed: 02/19/01 1:39 PM
Page 4 of 20
The fine for speeding on a road with a speed limit of 45
kilometers per hour (kph) is 50; plus 5 for each kph from
46 to 55 kph; plus 10 for each kph from 56 to 65 kph; plus
20 for each kph from 66 kph and above. Graph the
piecewise function that describes the cost of the ticket.
The fine (Y) as a function of kilometers per hour (X) is:
Y = 0 0 < X

45
Y = 50 + 5 (X
N
45) 45 < X

55
Y = 50 + 5
…
10 + 10 (X
N
55) 55 < X

65
Y = 50 + 5
…
10 + 10
…
10 + 20 (X
N
65) 65 < X
1. Press
z
. Select
Func and the default settings.
2. Press
o
. Turn off all functions and stat plots. Enter the
Y=
function to describe the fine. Use the
TEST
menu
operations to define the piecewise function. Set the
graph style for
Y
1
to
í
(dot).
3. Press
p
and set Xmin=
L
2, Xscl=10, Ymin=
L
5, and
Yscl=10. Ignore Xmax and Ymax; they are set by
@
X
and
@
Y
in step 4.
4. Press
y
[
QUIT
] to return to the home screen. Store 1 to
@
X
, and then store 5 to
@
Y
.
@
X
and
@
Y
are on the
VARS Window X/Y
secondary menu.
@
X
and
@
Y
specify
the horizontal and vertical distance between the centers
of adjacent pixels. Integer values for
@
X
and
@
Y
produce
nice values for tracing.
5. Press
r
to plot the function. At what speed does
the ticket exceed 250?
Graphing Piecewise Functions
Problem
Procedure