Texas Instruments PLUS TI-89 - Manual (Page 535)

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,
4ù sin(x),2x+3),5ì x^2) ¸
when() is helpful for defining recursive
functions.
when(n>0,nù factoral(nì 1),1)
! factoral(n) ¸ Done
factoral(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
:While i<=20
: temp+1/i! temp
: i+1! i
:EndWhile
:Disp "sum of reciprocals up to
20",temp
©
“With” See | , page 538.
xor MATH/Test menu
Boolean 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