Rational Expressions R6_NOTES MATH 1111 Section R.6(p. 35-43) Skills Determine the domain of a rational expression. Simplify rational expressions. Multiply, divide, add, and subtract rational expressions. Simplify complex rational expressions. Vocabulary domain equivalent expressions least common denominator (LCD) A rational expressionis the quotient of two polynomials. The Domain of Rational Expressions The domain of an algebraic expression is the set of all real numbers for which the expression is defined. Division by zero is not defined, so any number that makes the denominator 0 is not in the domain of a rational expression. Ex. Find the domain of the following expressions. Describe the domain using set-builder notation. Simplifying, Multiplying, & Dividing Rational Expressions To simplify rational expressions, we use the fact that Ex. Ex. Equivalent expressionshave the same value for all numbers that are in both domains.
NOTE: When multiplying or dividing rational expressions, it is usually best to factor each expression first.