/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 95 Rationalize the numerator. $$ ... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Rationalize the numerator. $$ \frac{1-\sqrt{5}}{3} $$

Short Answer

Expert verified
The rationalized numerator form is \( \frac{-4}{3(1+\sqrt{5})} \).

Step by step solution

01

Identify the Problem

We need to rationalize the numerator of the expression \( \frac{1-\sqrt{5}}{3} \). This process involves eliminating the radical (\(\sqrt{5}\)) from the numerator.
02

Find the Conjugate

To rationalize, we multiply both the numerator and the denominator by the conjugate of the numerator, which is \(1+\sqrt{5}\). This helps in eliminating the square root from the numerator.
03

Multiply Numerator and Denominator

Multiply the numerator and denominator by \(1+\sqrt{5}\):\[\frac{(1-\sqrt{5})(1+\sqrt{5})}{3(1+\sqrt{5})}\]
04

Simplify the Numerator

Use the formula for the difference of squares, \((a-b)(a+b) = a^2 - b^2\), to simplify the numerator: \(1^2 - (\sqrt{5})^2 = 1 - 5 = -4\).
05

Simplify the Expression

Substitute back into the fraction to get:\[\frac{-4}{3(1+\sqrt{5})}\] This is the rationalized form of the original expression with respect to the numerator.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Conjugate
In mathematics, a **conjugate** is a technique used to eliminate square roots (radicals) from the numerator or denominator of a fraction. Conjugates are paired expressions involving the change of a sign between two terms. For example, the conjugate of the expression \(1 - \sqrt{5}\) is \(1 + \sqrt{5}\).
  • By multiplying an expression by its conjugate, we aim to cancel out radicals using a special algebraic product called the difference of squares.
  • This simplifies the expression because multiplying by the conjugate results in whole numbers.
Multiplying with conjugates is like using a mirror image, where the operation maintains balance by making the denominator or numerator free of square roots.
Difference of squares
The **difference of squares** is a powerful algebraic identity represented by the formula:\[(a - b)(a + b) = a^2 - b^2\]This identity allows you to simplify products of conjugates. Here's how it works:
  • In the given exercise, the conjugate \( (1+\sqrt{5}) \) was used to multiply the numerator \( (1-\sqrt{5})(1+\sqrt{5}) \) which forms a difference of squares scenario.
  • Applying the formula, \(a = 1\) and \(b = \sqrt{5}\), results in \(1^2 - (\sqrt{5})^2\).
  • Calculate each square to get \(1 - 5\), which simplifies directly to \(-4\).
This transformation elegantly eradicates the radical, simplifying the fraction to have non-radical numbers in crucial places.
Simplifying radicals
**Simplifying radicals** is another key concept in algebra that involves removing square roots from expressions when possible. Here are the steps typically involved:
  • Identify and multiply by a conjugate to eliminate radicals from the numerator or denominator.
  • Calculate using the difference of squares to simplify radical terms.
  • Re-write the expression without the radical, ensuring it is simpler and more manageable.
For the example given, after using the conjugate and the difference of squares, the numerator became a simple integer \(-4\), allowing the fraction \(\frac{-4}{3(1+\sqrt{5})}\) to be more streamlined. Radical simplification is common in making expressions easier to work with for further algebraic operations.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Study anywhere. Anytime. Across all devices.