Texas Instruments TI-89, TI-92

Appendix A: Functions and Instructions 419

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 419 of 132

cFactor() MATH/Algebra/Complex menu

cFactor(expression1[, var]) ⇒ expression

cFactor(list1[,var]) ⇒ list

cFactor(matrix1[,var]) ⇒ matrix

cFactor(expression1) returns expression1

factored with respect to all of its variables

over a common denominator.

expression1 is factored as much as possible

toward linear rational factors even if this

introduces new non-real numbers. This

alternative is appropriate if you want

factorization with respect to more than one

variable.

cFactor(a^3ùx^2+aùx^2+a^3+a)

aø(a + ëi)ø(a + i)ø(x + ëi)ø(x + i)

cFactor(x^2+4/9) ¸

(3øx + ë2øi)ø(3øx + 2ø i)

cFactor(x^2+3) ¸xñ + 3

cFactor(x^2+a) ¸xñ + a

cFactor(expression1,var) returns expression1

factored with respect to variable var.

expression1 is factored as much as possible

toward factors that are linear in var, with

perhaps non-real constants, even if it

introduces irrational constants or

subexpressions that are irrational in other

variables.

The factors and their terms are sorted with

var as the main variable. Similar powers of

var are collected in each factor. Include var if

factorization is needed with respect to only

that variable and you are willing to accept

irrational expressions in any other variables

to increase factorization with respect to var.

There might be some incidental factoring

with respect to other variables.

cFactor(a^3ùx^2+aùx^2+a^3+a,x)

aø(añ + 1)ø(x + ë i)ø(x + i)

cFactor(x^2+3,x) ¸

(x + ‡3ø i)ø(x + ë‡3ø i)

cFactor(x^2+a,x) ¸

(x + ‡aøëi)ø(x + ‡aø i)

For the AUTO setting of the Exact/Approx

mode, including var also permits

approximation with floating-point

coefficients where irrational coefficients

cannot be explicitly expressed concisely in

terms of the built-in functions. Even when

there is only one variable, including var might

yield more complete factorization.

Note: See also factor().

cFactor(x^5+4x^4+5x^3ì6xì3)

x5 + 4øx4 + 5øx3 ì6øxì3

cFactor(ans(1),x) ¸

(

x ì.965

)

(

x +.6

)

(

x + 2.

)

(x + 1.11 ì 1.07øi)ø

(x + 1.11 + 1.07øi)

char() MATH/String menu

char(integer) ⇒ character

Returns a character string containing the

character numbered integer from the

TI-89 / TI-92 Plus character set. See

Appendix B for a complete listing of

character codes.

The valid range for integer is 0–255.

char(38) ¸"&"

char(65) ¸"A"