Texas Instruments TI-89 User Manual

Previews

Parametric Graphing

Graph the parametric equations describing the path of a ball kicked at an angle (q) of 60¡
with an initial velocity (v

) of 15 meters/sec. The gravity constant g = 9.8 meters/sec

Ignoring air resistance and other drag forces, what is the maximum height of the ball and
when does it hit the ground?

Steps and keystrokes

Display

1. Display the

MODE

dialog box. For

Graph

mode, select

PARAMETRIC

Press

3 B 2 ¸

2. Display and clear the

Y= Editor

. Then

define the horizontal component
xt1(t) = v

t cos q.

Enter values for v

and q.

Press

8 # , 8 ¸ ¸ 15T p

2 X 60 2 “ d ¸
Type T

p 2 X, not T 2 X.

Enter a ¡ symbol by typing either 2 “
or

2 I 2 1. This ensures a number

is interpreted as degrees, regardless of
the angle mode.

xt1(t)=15t

…

cos(60

)