Skip to main content
Ch. R - Review of Basic Concepts
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063Not the one you use?Change textbook
Chapter 1, Problem 19a

Find the domain of each rational expression. x3 - 1 / x - 1

Verified step by step guidance
1
Identify the rational expression given: \(\frac{x^3 - 1}{x - 1}\).
Recall that the domain of a rational expression excludes values that make the denominator zero, because division by zero is undefined.
Set the denominator equal to zero and solve for \(x\): \(x - 1 = 0\).
Solve the equation to find the value(s) to exclude from the domain: \(x = 1\).
Conclude that the domain is all real numbers except \(x = 1\), which can be written in interval notation as \((-\infty, 1) \cup (1, \infty)\).

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Rational Expressions

A rational expression is a fraction where both the numerator and denominator are polynomials. Understanding rational expressions involves knowing how to simplify, factor, and analyze these fractions, especially focusing on restrictions caused by the denominator.
Recommended video:
Guided course
02:58
Rationalizing Denominators

Domain of a Function

The domain of a function is the set of all input values (x-values) for which the function is defined. For rational expressions, the domain excludes values that make the denominator zero, as division by zero is undefined.
Recommended video:
3:51
Domain Restrictions of Composed Functions

Factoring Polynomials

Factoring polynomials involves rewriting a polynomial as a product of simpler polynomials. This skill helps identify values that make the denominator zero by factoring and setting each factor equal to zero to find restrictions on the domain.
Recommended video:
Guided course
07:30
Introduction to Factoring Polynomials