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Ch. P - Fundamental Concepts of Algebra
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Non è quello che usi tu?Cambia libro di testo
Capitolo 1, Problema 52

Rationalize the denominator.
53−1\(\frac{5}{\sqrt3-1}\)

Guida verificata passo dopo passo
1
Identify the expression to rationalize: \(\frac{5}{\sqrt{3} - 1}\). The goal is to eliminate the square root from the denominator.
Multiply both the numerator and the denominator by the conjugate of the denominator. The conjugate of \(\sqrt{3} - 1\) is \(\sqrt{3} + 1\). So multiply by \(\frac{\sqrt{3} + 1}{\sqrt{3} + 1}\).
Apply the multiplication: The numerator becomes \(5(\sqrt{3} + 1)\), and the denominator becomes \((\sqrt{3} - 1)(\sqrt{3} + 1)\).
Use the difference of squares formula for the denominator: \((a - b)(a + b) = a^2 - b^2\). Here, \(a = \sqrt{3}\) and \(b = 1\), so the denominator simplifies to \((\sqrt{3})^2 - 1^2\).
Simplify the denominator to a rational number and write the final expression as \(\frac{5(\sqrt{3} + 1)}{3 - 1}\). This completes the rationalization process.

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Rationalizing the Denominator

Rationalizing the denominator involves eliminating any radicals (such as square roots) from the denominator of a fraction. This is done to simplify the expression and make it easier to work with. Typically, this is achieved by multiplying the numerator and denominator by a suitable expression that removes the radical.
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Rationalizing Denominators

Conjugates of Binomials

The conjugate of a binomial expression like (√3 - 1) is (√3 + 1). Multiplying a binomial by its conjugate results in a difference of squares, which eliminates the square root terms. This property is essential for rationalizing denominators that contain binomials with radicals.
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Complex Conjugates

Difference of Squares Formula

The difference of squares formula states that (a - b)(a + b) = a² - b². This formula is used to simplify expressions when multiplying conjugates. In rationalizing denominators, it helps convert expressions like (√3 - 1)(√3 + 1) into 3 - 1 = 2, removing the radical from the denominator.
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