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Rational Expressions. Section 0.5. Rational Expressions and domain restrictions. Rational number- ratio of two integers with the denominator not equal to zero. Rational expression- ratio or quotient of two polynomials with the denominator not equal to zero Examples: Rational number:
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Rational Expressions Section 0.5
Rational Expressions and domain restrictions • Rational number- ratio of two integers with the denominator not equal to zero. • Rational expression- ratio or quotient of two polynomials with the denominator not equal to zero Examples: Rational number: Rational expression: where x = 6
Domain- set of real numbers that your algebraic expression is defined. • Think about domain as what values are OK to plug into your equation. • For rational expressions our domain will not be defined for the values that make the denominator zero. • What is the domain for: Answer: All Real numbers except x = -3
Find the domain for each algebraic expression Domain: All real numbers Domain: All real numbers except x = 0 Domain: All real numbers except Domain: All real numbers
Find the domain for each algebraic expression Domain: All real numbers except x = 0 and x = 5 Domain: All real numbers except x = 4 and x = -4
Reduce the rational expression Where x = -5 Where x = -1
Multiply the rational expressions and simplify Check domain at factored step: Domain: All reals except:
Multiply Domain Restrictions: if!
Divide the rational expressions Domain: All reals except -2, 0, and 2
Divide Domain: All reals except 0, 3 and -3
Adding Rational Expressions Need to reduce D: all reals except x = -2
Adding Rational Expressions Need a Common Denominator D: All reals except x = -1/2 and x = 1