Texas Instruments TITANIUM TI-89 - Manual (Page 864)

864 Appendix A: Functions and Instructions
remain() MATH/Number menu
remain( expression1 , expression2 )
⇒ ⇒ ⇒ ⇒ expression
remain( list1 , list2 ) ⇒ ⇒ ⇒ ⇒ list
remain( matrix1 , matrix2 )
⇒ ⇒ ⇒ ⇒ matrix
Returns the remainder of the first argument with
respect to the second argument as defined by the
identities:
remain(x,0)  x
remain(x,y)  xì yùiPart(x/y)
remain(7,0) ¸ 7
remain(7,3) ¸ 1
remain(л 7,3)
¸ л
1
remain(7,ë 3) ¸ 1
remain(л 7,л 3) ¸ л 1
remain({12,л 14,16},{9,7,л 5})
¸
{3 0 1}
As a consequence, note that remain( ì x,y) 
ì remain(x,y) . The result is either zero or it has
the same sign as the first argument.
Note: See also mod() .
remain([9,л 7;6,4],[4,3;4,л 3])
¸
[
1 л1
2 1
]
Rename CATALOG
Rename oldVarName , newVarName
Renames the variable oldVarName as newVarName .
{1,2,3,4}! L1 ¸ {1,2,3,4}
Rename L1, list1
¸
Done
list1 ¸ {1,2,3,4}
Request CATALOG
Request
promptString, , , , var [,alphaOn/Off]
If Request is inside a Dialog...EndDlog construct, it
creates an input box for the user to type in data. If it
is a stand-alone instruction, it creates a dialog box
for this input. In either case, if var contains a string,
it is displayed and highlighted in the input box as a
default choice. promptString must be
{ 20
characters.
This instruction can be stand-alone or part of a
dialog construct.
Request "Enter text",t,1 ¸
The argument turned on alpha-lock in the
above example.
The optional alphaOn/Off argument can be any
expression. If it evaluates to zero, alpha-lock is set
to OFF. If it evaluates to anything other than zero,
alpha-lock is set to ON. If the optional argument is
not used, alpha-lock defaults to ON.
If more than one Request command appears within
a Dialog...EndDlog construct, the first alpha setting
is used and subsequent ones are ignored.
Request “Enter number”,n,0
The argument turned off alpha-lock in the
above example.
Return CATALOG
Return [ expression ]
Returns expression as the result of the function.
Use within a Func ... EndFunc block, or
Prgm ... EndPrgm block.
Note: Use Return without an argument to exit a
program.
Note: Enter the text as one long line on the
Home screen (without line breaks).
Define factoral(nn)=Func
:local answer,count:1! answer
:For count,1,nn
:answerù count! answer:EndFor
:Return answer:EndFunc ¸ Done
factoral(3) ¸ 6