128 Chapter 7: Parametric Graphing
07PARAM.DOC TI-89/TI-92 Plus: Parametric Graphing (English) Susan Gullord Revised: 02/23/01 10:56 AM Printed: 02/23/01 2:13 PM Page 128 of 6
Steps
³
TI-89
Keystrokes
›
TI-92 Plus
Keystrokes Display
1. Display the
MODE dialog box.
For Graph mode, select
PARAMETRIC.
3
B2
¸
3
B2
¸
2. Display and clear the Y= Editor.
Then define the horizontal
component xt1(t) = v0t cos q.
Enter values for v
0
and q.
TI-89: T
ype
T
p2X
, not
T 2X
.
TI-92 Plus:
Type
T
pX
, not
T X
.
Enter a ¡ symbol by typing either
2“
or
2I 2 1
. This ensures a
number is interpreted as degrees,
regardless of the angle mode.
¥#
ƒ8¸
¸
15Tp
2X60
2“d¸
¥#
ƒ8¸
¸
15Tp
X60
2“d¸
xt1(t)=15tùcos(60¡)
3. Define the vertical component
yt1(t) = v0t sin q – (g/2)t2.
Enter values for v
0
,q, and g.
¸
15Tp
2W60
2“d|c
9.8e2d
TZ2¸
¸
15Tp
W60
2“d|c
9.8e2d
TZ2¸
4. Display the Window Editor.
Enter Window variables
appropriate for this example.
You can press either
D
or
¸
to
enter a value and move to the next
variable.
¥$
0D3D
.02D·2D
25D5D
·2D10D
5
¥$
0D3D
.02D·2D
25D5D
·2D10D
5
5. Graph the parametric equations
to model the path of the ball.
¥% ¥%
6. Select
Trace. Then move the
cursor along the path to find the:
¦ y value at maximum height.
¦ t value where the ball hits the
ground.
…
Bor A
as necessary
…
Bor A
as necessary
Preview of Parametric Graphing
Graph the parametric equations describing the path of a ball kicked at an angle (q) of 60¡
with an initial velocity (v0) of 15 meters/sec. The gravity constant g = 9.8 meters/sec2.
Ignoring air resistance and other drag forces, what is the maximum height of the ball and
when does it hit the ground?