Using the Difference of Cubes Formula

Oct 13, 2025 by wbrum.org 83 views

Introduction

In algebra, factoring is a crucial concept that helps us simplify complex expressions and solve equations. When we encounter a polynomial expression like y = x³ - x, our first instinct might be to try and factor it out. However, this particular expression has a unique twist that requires a deeper understanding of algebraic concepts. In this article, we will delve into the world of factoring and explore the common factor of y = x³ - x.

What is Factoring?

Factoring is the process of expressing a polynomial expression as a product of simpler expressions, called factors. These factors can be numbers, variables, or a combination of both. Factoring helps us simplify complex expressions, identify common factors, and solve equations. It's an essential tool in algebra that enables us to manipulate expressions and equations with ease.

The Common Factor: y = x³ - x

The expression y = x³ - x appears to be a simple polynomial, but it has a hidden pattern that makes it challenging to factor. At first glance, it seems like we can factor out a common factor of x, but that's not the case. The expression can be rewritten as y = x(x² - 1), but this is not the only possible factorization.

Using the Difference of Cubes Formula

One way to factor the expression y = x³ - x is to use the difference of cubes formula. The difference of cubes formula states that a³ - b³ = (a - b)(a² + ab + b²). In this case, we can rewrite the expression as x³ - x = x(x² - 1) = (x - 1)(x² + x + 1). This factorization reveals a common factor of (x - 1).

Using the Sum and Difference of Cubes Formula

Another way to factor the expression y = x³ - x is to use the sum and difference of cubes formula. The sum and difference of cubes formula states that a³ + b³ = (a + b)(a² - ab + b²) and a³ - b³ = (a - b)(a² + ab + b²). In this case, we can rewrite the expression as x³ - x = (x - 1)(x² + x + 1).

Using the Synthetic Division Method

The synthetic division method is another way to factor the expression y = x³ - x. This method involves dividing the polynomial by a linear factor, in this case, (x - 1). By performing synthetic division, we can determine that the quotient is x² + x + 1.

Conclusion

In conclusion, the common factor of y = x³ - x is not immediately apparent. However, by using various algebraic techniques, such as the difference of cubes formula, the sum and difference of cubes formula, and synthetic division, we can factor the expression and reveal a common factor of (x - 1). Factoring is an essential tool in algebra that enables us to simplify complex expressions, identify common factors, and solve equations. By mastering factoring techniques, we can tackle even the most challenging algebraic expressions.

Common Factor: y = x³ - x

Method	Factorization
Difference of Cubes Formula	(x - 1)(x² + x + 1)
Sum and Difference of Cubes Formula	(x - 1)(x² + x + 1)
Synthetic Division Method	(x - 1)(x² + x + 1)

Frequently Asked Questions

Q: What is the common factor of y = x³ - x?

A: The common factor of y = x³ - x is (x - 1).

Q: How can I factor the expression y = x³ - x?

A: You can use various algebraic techniques, such as the difference of cubes formula, the sum and difference of cubes formula, and synthetic division.

Q: What is the quotient when the expression y = x³ - x is divided by (x - 1)?

A: The quotient is x² + x + 1.

References

[1] "Algebra" by Michael Artin
[2] "Calculus" by Michael Spivak
[3] "Mathematics for Computer Science" by Eric Lehman and Tom Leighton

Glossary

Factoring: The process of expressing a polynomial expression as a product of simpler expressions, called factors.
Difference of Cubes Formula: A formula that states a³ - b³ = (a - b)(a² + ab + b²).
Sum and Difference of Cubes Formula: A formula that states a³ + b³ = (a + b)(a² - ab + b²) and a³ - b³ = (a - b)(a² + ab + b²).
Synthetic Division Method: A method of dividing a polynomial by a linear factor.
Q&A: Common Factor y = x³ - x =====================================

Frequently Asked Questions

Q: What is the common factor of y = x³ - x?

A: The common factor of y = x³ - x is (x - 1).

Q: How can I factor the expression y = x³ - x?

A: You can use various algebraic techniques, such as the difference of cubes formula, the sum and difference of cubes formula, and synthetic division.

Q: What is the quotient when the expression y = x³ - x is divided by (x - 1)?

A: The quotient is x² + x + 1.

Q: Can I use other methods to factor the expression y = x³ - x?

A: Yes, you can use other methods such as grouping, substitution, and elimination. However, the difference of cubes formula, the sum and difference of cubes formula, and synthetic division are the most efficient methods for factoring this expression.

Q: How do I apply the difference of cubes formula to factor the expression y = x³ - x?

A: To apply the difference of cubes formula, you need to rewrite the expression as a³ - b³, where a = x and b = 1. Then, you can use the formula to factor the expression as (a - b)(a² + ab + b²).

Q: What is the significance of the common factor (x - 1) in the expression y = x³ - x?

A: The common factor (x - 1) is significant because it allows us to simplify the expression and identify the quotient x² + x + 1.

Q: Can I use the sum and difference of cubes formula to factor the expression y = x³ - x?

A: Yes, you can use the sum and difference of cubes formula to factor the expression y = x³ - x. The sum and difference of cubes formula states that a³ + b³ = (a + b)(a² - ab + b²) and a³ - b³ = (a - b)(a² + ab + b²).

Q: How do I apply the sum and difference of cubes formula to factor the expression y = x³ - x?

A: To apply the sum and difference of cubes formula, you need to rewrite the expression as a³ - b³, where a = x and b = 1. Then, you can use the formula to factor the expression as (a - b)(a² + ab + b²).

Q: What is the significance of the quotient x² + x + 1 in the expression y = x³ - x?

A: The quotient x² + x + 1 is significant because it represents the simplified expression after factoring out the common factor (x - 1).

Q: Can I use synthetic division to factor the expression y = x³ - x?

A: Yes, you can use synthetic division to factor the expression y = x³ - x. Synthetic division is a method of dividing a polynomial by a linear factor.

Q: How do I apply synthetic division to factor the expression y = x³ - x?

A: To apply synthetic division, you need to divide the polynomial by the linear factor (x - 1). The result will be the quotient x² + x + 1.

Additional Resources

[1] "Algebra" by Michael Artin
[2] "Calculus" by Michael Spivak
[3] "Mathematics for Computer Science" by Eric Lehman and Tom Leighton

Glossary

Factoring: The process of expressing a polynomial expression as a product of simpler expressions, called factors.
Difference of Cubes Formula: A formula that states a³ - b³ = (a - b)(a² + ab + b²).
Sum and Difference of Cubes Formula: A formula that states a³ + b³ = (a + b)(a² - ab + b²) and a³ - b³ = (a - b)(a² + ab + b²).
Synthetic Division Method: A method of dividing a polynomial by a linear factor.

Common Factor: y = x³ - x

Method	Factorization
Difference of Cubes Formula	(x - 1)(x² + x + 1)
Sum and Difference of Cubes Formula	(x - 1)(x² + x + 1)
Synthetic Division Method	(x - 1)(x² + x + 1)

Conclusion

In conclusion, the common factor of y = x³ - x is (x - 1). We can use various algebraic techniques, such as the difference of cubes formula, the sum and difference of cubes formula, and synthetic division, to factor the expression and reveal the quotient x² + x + 1. Factoring is an essential tool in algebra that enables us to simplify complex expressions, identify common factors, and solve equations. By mastering factoring techniques, we can tackle even the most challenging algebraic expressions.