Calculator User Manual
518      Appendix  A:  Functions  and  Instructions
8992APPA.DOC TI-89 / TI-92 Plus: Appendix A (US English) Susan Gullord Revised: 02/23/01 1:48 PM Printed: 02/23/01 2:21 PM Page 518 of 132
Nest 
when()
 to define expressions that have
more than two pieces.
TI-89: "
TI-92 Plus: 
¥"
ClrGraph
¸
Done
Graph when(x<0,when(x<
ë
p,
4
ù
sin(x),2x+3),5
ì
x^2)
¸
when()
 is helpful for defining recursive
functions.
when(n>0,n
ù
factoral(n
ì
1),1)
!
factora
l(
n
)
¸
Done
factora
l(
3
)
¸
6
3
! 
¸
6
While
CATALOG
While condition
    block
EndWhile
Executes the statements in 
block
 as long as
condition
 is true.
block
 can be either a single statement or a
sequence of statements separated with the “:”
character.
Program segment:
©
:
1
!
i
:0
!
temp
:W
h
i
l
e i<=20
: temp+
1/
i
!
temp
: i+
1
!
i
:En
d
W
h
i
l
e
:Disp "sum of reciproca
l
s up to
20",temp
©
“With”
See 
|
, page 538.
xor
MATH/Test menu
B
oolean expression1 xor Boolean expression2 
⇒
Boolean expression
Returns 
true
 if 
Boolean expression1
 is 
true
 and
Boolean expression2
 is false, or vice versa.
Returns 
false
 if 
Boolean expression1
 and
Boolean expression2
 are both true or both
false. Returns a simplified Boolean
expression if either of the original Boolean
expressions cannot be resolved to true or
false.
Note: See 
or
.
true xor true
¸
false
(5>3) xor (3>5)
¸
true










