Texas Instruments TI-89 User Manual - Page 791

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(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 nonreal 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. 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(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) 9 cFactor(x^2+3) ¸ xñ + 3 cFactor(x^2+a) ¸ xñ + a 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) cFactor(x^5+4x^4+5x^3ì6xì3) ¸ x5 + 4øx4 + 5øx3 ì6øxì3 cFactor(ans(1),x) ¸ (x ì.965)ø(x +.612)ø(x + 2.13)ø (x + 1.11 ì 1.07øi)ø (x + 1.11 + 1.07øi) char( ) MATH/String menu char(integer) ⇒ character char(38) ¸ "&" Returns a character string containing the char(65) ¸ "A" character numbered integer from the TI-89 Titanium/Voyage™ 200 character set. See Appendix B for a complete listing of character codes. The valid range for integer is 0-255. checkTmr() CATALOG checkTmr(starttime) ⇒ integer Returns an integer representing the number of seconds that have elapsed since a timer was started. starttime is an integer returned from the startTmr() function. You can also use a list or matrix of starttime integers. Valid starttime integers must fall between 0 and the current time of the clock. You can run multiple timers simultaneously. Note: See also startTmr() and timeCnv(). startTmr() ¸ 148083315 checkTmr(148083315) 34 startTmr()!Timer1 © startTmr()!Timer2 © checkTmr(Timer1)!Timer1Value © checkTmr(Timer2)!Timer2Value Appendix A: Functions and Instructions 791