Texas Instruments TI-89, TI-92

434 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 434 of 132

Define progName(arg1Name, arg2Name, ...) = Prgm

block

EndPrgm

Creates progName as a program or

subprogram, but cannot return a result using

Return. Can execute a block of multiple

statements.

block can be either a single statement or a

series of statements separated with the “:”

character. block also can include expressions

and instructions (such as If, Then, Else, and

For) without restrictions.

Note: It is usually easier to author and edit a

program block in the Program Editor rather

than on the entry line.

Define listinpt()=prgm:Local

n,i,str1,num:InputStr "Enter

name of list",str1:Input "No.

of elements",n:For

i,1,n,1:Input "element

"&string(i),num:

num!#str1[i]:EndFor:EndPrgm

Done

listinpt() ¸Enter name of lis

DelFold CATALOG

DelFold folderName1[, folderName2] [, folderName3] ...

Deletes user-defined folders with the names

folderName1, folderName2, etc. An error

message is displayed if the folders contain

any variables.

Note: You cannot delete the main folder.

NewFold games ¸Done

(creates the folder games)

DelFold games ¸Done

(deletes the folder games)

DelVar CATALOG

DelVar var1[, var2] [, var3] ...

Deletes the specified variables from memory.

2!a ¸2

(

a+2

)

¸1

Var a

Done

(

a+2

)

¸(

a + 2

)ñ

deSolve() MATH/Calculus menu

deSolve(1stOr2ndOrderOde, independentVar,

dependentVar) ⇒ a general solution

Returns an equation that explicitly or

implicitly specifies a general solution to the

1st- or 2nd-order ordinary differential

equation (ODE). In the ODE:

• Use a prime symbol ( ' , press 2È) to

denote the 1st derivative of the dependent

variable with respect to the independent

variable.

• Use two prime symbols to denote the

corresponding second derivative.

The ' symbol is used for derivatives within

deSolve() only. In other cases, use d().

The general solution of a 1st-order equation

contains an arbitrary constant of the form

@k, where k is an integer suffix from 1

through 255. The suffix resets to 1 when you

use ClrHome or ƒ8: Clear Home. The

solution of a 2nd-order equation contains two

such constants.

Note: To type a prime symbol ( ' ), press

2È.

deSolve(y''+2y'+y=x^2,x,y)¸

y=(@1øx+@2)øeëx+xñì4øx+6

right(ans(1))!temp ¸

(@1øx+@2)øeëx+xñì4øx+6

d(temp,x,2)+2ùd(temp,x)+tempìx^2

¸0

DelVar temp ¸Done