Texas Instruments TI-89 Titanium User Manual page 84

Steps and keystrokes
2. Display the Home screen. Then store the
radius, 5, in variable r.
@ " 5 9 j R ¸
3. Display and clear the
define y1(x) =
a circle.
In function graphing, you must define
separate functions for the top and bottom
halves of a circle.
@ 8 # , 8 ¸ ¸ 2 ]
j R Z 2 | X Z 2 d ¸
4. Define y2(x) =
the bottom half of the circle.
The bottom half is the negative of the top
half, so you can define y2(x) = Ly1(x).
Use the full function name
simply y1.
Press ¸ ? Y 1 c X d ¸
Previews
. Then
Y= Editor
2 2
( )
r – x , the top half of
2 2
– r – x , the function for
, not
y1(x)
Display
!
5 r
81