Chapter 17: Activities
309
4. Press
y 5
to return to the home screen. 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 Inequalities
Problem
Graph the inequality 0.4x
3
N
3x + 5 < 0.2x + 4. Use the
TEST
menu operations to explore the values
of X where the inequality is true and where it is false.
Note: You can also investigate graphing inequalities using the Inequality Graphing application.
The application is pre-loaded on your TI-84 Plus and can be downloaded from
Procedure
1. Press
z
. Select
Dot
,
Simul
, and the default settings. Setting
Dot
mode changes all graph
style icons to
í
(dot) in the
Y=
editor.
2. Press
o
. Turn off all functions and stat plots. Enter the left side of the inequality as
Y4
and the
right side as
Y5
.
3. Enter the statement of the inequality as
Y6
. This function evaluates to
1
if true or
0
if false.
Note
: You can use the YVARS shortcut menu to paste Y4 and Y5 in the Y= editor.
4. Press
q
6
to graph the inequality in the standard window.
