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Ch. 3 - Polynomial and Rational Functions
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Non è quello che usi tu?Cambia libro di testo
Capitolo 4, Problema 3

Find the domain of each rational function. g(x)=3x2/(x−5)(x+4)

Guida verificata passo dopo passo
1
Identify the rational function given: \(g(x) = \frac{3x^{2}}{(x - 5)(x + 4)}\).
Recall that the domain of a rational function includes all real numbers except where the denominator is zero, because division by zero is undefined.
Set the denominator equal to zero to find the values that are not in the domain: \((x - 5)(x + 4) = 0\).
Solve each factor for zero: \(x - 5 = 0\) gives \(x = 5\), and \(x + 4 = 0\) gives \(x = -4\).
Conclude that the domain of \(g(x)\) is all real numbers except \(x = 5\) and \(x = -4\).

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Rational Functions

A rational function is a ratio of two polynomials, expressed as f(x) = P(x)/Q(x). Understanding rational functions involves recognizing that the function is undefined where the denominator Q(x) equals zero, which affects the domain.
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The domain of a function is the set of all input values (x-values) for which the function is defined. For rational functions, the domain excludes values that make the denominator zero, since division by zero is undefined.
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To find the domain of a rational function, identify the values of x that make the denominator zero by solving Q(x) = 0. These values are excluded from the domain because they cause the function to be undefined.
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