Texas Instruments TI89TITANIUM User Manual - Page 856

propFrac( ) MATH/Algebra menu propFrac(expression1[, var]) ⇒ expression propFrac(4/3) ¸ propFrac(rational_number) returns rational_number as the sum of an integer and a fraction having the same sign and a greater denominator magnitude than numerator magnitude. propFrac(ë 4/3) ¸ propFrac(rational_expression,var) returns the sum of proper ratios and a polynomial with respect to var. The degree of var in the denominator exceeds the degree of var in the numerator in each proper ratio. Similar powers of var are collected. The terms and their factors are sorted with var as the main variable. If var is omitted, a proper fraction expansion is done with respect to the most main variable. The coefficients of the polynomial part are then made proper with respect to their most main variable first and so on. propFrac((x^2+x+1)/(x+1)+ (y^2+y+1)/(y+1),x) ¸ propFrac(ans(1)) For rational expressions, propFrac() is a faster but less extreme alternative to expand(). 1 + 1/3 ë 1ì 1/3 PtChg CATALOG PtChg x, y PtChg xList, yList Note: PtChg through PtText show continuing similar examples. Displays the Graph screen and reverses the screen PtChg 2,4 ¸ pixel nearest to window coordinates (x, y). PtOff CATALOG PtOff x, y PtOff xList, yList Displays the Graph screen and turns off the screen pixel nearest to window coordinates (x, y). PtOff 2,4 ¸ PtOn CATALOG PtOn x, y PtOn xList, yList PtOn 3,5 ¸ Displays the Graph screen and turns on the screen pixel nearest to window coordinates (x, y). ptTest() CATALOG ptTest (x, y) ⇒ Boolean constant expression ptTest (xList, yList) ⇒ Boolean constant expression ptTest(3,5) ¸ true Returns true or false. Returns true only if the screen pixel nearest to window coordinates (x, y) is on. 856 Appendix A: Functions and Instructions