Texas Instruments TI-89 User Manual - Page 879

Due to default cancellation of the greatest common divisor from the numerator and denominator of ratios, solutions might be solutions only in the limit from one or both sides. (x+1)(xì 1)/(xì 1)+xì 3 ¸ solve(entry(1)=0,x) ¸ entry(2)|ans(1) ¸ limit(entry(3),x,1) ¸ 2ø xì 2 x = 1 undef 0 For inequalities of types or >, explicit solutions are unlikely unless the inequality is linear and contains only var. For the EXACT setting of the Exact/Approx mode, portions that cannot be solved are returned as an implicit equation or inequality. solve(5xì 2 , 2x,x) ¸ x , 2/3 exact(solve((xì a)e^(x)=ë xù (xì a),x)) ¸ ex + x = 0 or x = a Use the "|" operator to restrict the solution interval and/or other variables that occur in the equation or inequality. When you find a solution in one interval, you can use the inequality operators to exclude that interval from subsequent searches. false is returned when no real solutions are found. true is returned if solve() can determine that any finite real value of var satisfies the equation or inequality. Since solve() always returns a Boolean result, you can use "and," "or," and "not" to combine results from solve() with each other or with other Boolean expressions. In Radian angle mode: solve(tan(x)=1/x,x)|x>0 and x