/*! 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 53 Use the fact that \(x^{3}+y^{3}=... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Use the fact that \(x^{3}+y^{3}=\) \((x+y)\left(x^{2}-x y+y^{2}\right)\) to rationalize the denominator. $$\frac{1}{\sqrt[3]{3}+1}$$

Short Answer

Expert verified
Question: Rationalize the denominator of the fraction $$\frac{1}{\sqrt[3]{3}+1}$$ using the given identity: \(x^{3}+y^{3}=(x+y)(x^{2}-x y+y^{2})\). Answer: The rationalized form of the given fraction is $$\frac{3-\sqrt[3]{3}+1}{4}.$$

Step by step solution

01

Identify x and y

In this case, we must choose the values of x and y to match the denominator: \(\sqrt[3]{3} + 1\). So we pick \(x = \sqrt[3]{3}\) and \(y = 1\).
02

Apply the given identity

Substitute the values of \(x\) and \(y\) into the given identity: $$ x^{3}+y^{3}=(\sqrt[3]{3}+1)\left((\sqrt[3]{3})^{2}-\sqrt[3]{3}+1^{2}\right) $$
03

Simplify the given identity

Simplify the expression: $$ \sqrt[3]{3^3}+1^{3}=(\sqrt[3]{3}+1)\left(3-\sqrt[3]{3}+1\right) $$
04

Further simplification

Simplify the expression even more by removing the cube root and evaluate the sum: $$ 3 + 1 = (\sqrt[3]{3}+1)(3-\sqrt[3]{3}+1) $$
05

Find the conjugate

We need to find a conjugate of the denominator to rationalize it. To do so, we multiply both the numerator and the denominator of the given fraction by the conjugate of the denominator, which is \(3-\sqrt[3]{3}+1\). $$ \frac{1}{\sqrt[3]{3}+1} \cdot \frac{3-\sqrt[3]{3}+1}{3-\sqrt[3]{3}+1} $$
06

Multiply and simplify

Now, multiply the numerators and the denominators, and use the result from Step 4 to simplify the expression: $$ \frac{3-\sqrt[3]{3}+1}{(\sqrt[3]{3}+1)(3-\sqrt[3]{3}+1)} = \frac{3-\sqrt[3]{3}+1}{3+1} $$
07

Final simplification

Simplify the fraction and this will be our final answer: $$ \frac{3-\sqrt[3]{3}+1}{4} $$

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.

Cubic Roots
When we talk about cubic roots, we are referring to the number that, when multiplied by itself three times, gives the original number. For instance, if we have the cubic root of 27, it equals 3 because 3 multiplied by itself three times (i.e., 3 \( \times \) 3 \( \times \) 3) equals 27. Cubic roots are represented as \( \sqrt[3]{\cdot} \), which signifies that you are taking the cube root of a number.
In this exercise, we are dealing with \( \sqrt[3]{3} \), which indicates the cube root of 3.
  • To compute this manually, you would search for a number whose third power is close to or equals 3.
  • Cube roots can sometimes be approximate due to irrational numbers, which cannot be precisely expressed as a fraction or a decimal.
Understanding this concept is important because it helps us to simplify expressions involving roots, particularly when we try to rationalize denominators, as seen in the given exercise.
Factoring Identities
Factoring identities are special algebraic expressions that help us break down complex expressions into simpler factors. One commonly used identity is the sum of cubes, which is useful in our problem here. It is expressed as:\(x^3 + y^3 = (x + y)(x^2 - xy + y^2)\)This identity helps us factor cubic expressions conveniently, using a known pattern.
In the given task, we took\( x = \sqrt[3]{3} \) and\( y = 1 \).
Then, by substituting these values, we employ the identity to simplify the expression involving cubes.
  • Identities make algebraic manipulation manageable by providing a structured format for factoring.
  • They are essential tools for solving polynomial equations, simplifying, and rationalizing expressions.
Using these types of identities is particularly helpful when dealing with polynomials, because they can reduce complex expressions to simpler and more workable forms.
Algebraic Simplification
Algebraic simplification refers to the process of rewriting an algebraic expression in a simpler or more convenient form. In this particular exercise, we focus on simplifying the expression \( \frac{1}{\sqrt[3]{3}+1} \) by eliminating the irrational number in the denominator.
The core idea is to "rationalize" the denominator: to remove the cube root or any other irrational number.
  • To simplify, we find a conjugate based on the expression: \( 3-\sqrt[3]{3}+1 \).
  • Multiply both the numerator and the denominator by this conjugate to rationalize the expression (Step 5 of the solution).
  • By utilizing algebraic properties, such as the factoring identity, the expression becomes rationalized.
This process involves multiplying out and simplifying both the numerator and denominator until the unwanted terms cancel out or become simplified further. Following these steps results in a neat fractional form \( \frac{3-\sqrt[3]{3}+1}{4} \), which has a rationalized denominator.Algebraic simplification is crucial for solving equations, performing integration, differentiation, and general calculations in mathematics.

One App. One Place for Learning.

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

Get started for free

Most popular questions from this chapter

The U.S. Department of Commerce estimated that there were 54 million Internet users in the United States in 1999 and 85 million in 2002 . (a) Find an exponential function that models the number of Internet users in year \(x,\) with \(x=0\) corresponding to 1999 (b) For how long is this model likely to remain accurate? [Hint: The current U.S. population is about 305 million.]

Deal with the compound interest formula \(A=P(1+r)^{t},\) which was discussed in Special Topics \(5.2.A\). At what rate of interest (compounded annually) should you invest 500 dollars if you want to have 1500 dollars in 12 years?

The spread of a flu virus in a community of 45,000 people is given by the function $$f(t)=\frac{45,000}{1+224 e^{-.899 t}}$$ where \(f(t)\) is the number of people infected in week \(t\). (a) How many people had the flu at the outbreak of the epidemic? After three weeks? (b) When will half the town be infected?

The number of digital devices (such as MP3 players, handheld computers, cell phones, and PCs) in the world was approximately .94 billion in 1999 and is growing at a rate of \(28.3 \%\) a year. (a) Find the rule of a function that gives the number of digital devices (in billions) in year \(x,\) with \(x=0\) corresponding to 1999 (b) Approximately how many digital devices will be in use in \(2010 ?\) (c) If this model remains accurate, when will the number of digital devices reach 6 billion?

Between 1790 and \(1860,\) the population y of the United States (in millions) in year x was given by \(y=3.9572\left(1.0299^{\circ}\right),\) where \(x=0\) corresponds to \(1790 .\)F ind the U.S. population in the given year. $$1800$$

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.