Rational Expression

Definition

A rational expression is a mathematical expression that represents a ratio or fraction, where the numerator and denominator are both polynomial expressions. These expressions can be used to model and analyze various real-world situations involving rates, ratios, and proportions.

5 Must Know Facts For Your Next Test

1. Rational expressions can be used to model and analyze various real-world situations, such as rates, ratios, and proportions.
2. The numerator and denominator of a rational expression must both be polynomial expressions, and the denominator cannot be zero.
3. Rational expressions can be simplified by factoring the numerator and denominator and canceling common factors.
4. Partial fractions is a technique used to express a rational expression as a sum of simpler rational expressions, which can be useful for integration and other mathematical operations.
5. The properties of rational expressions, such as addition, subtraction, multiplication, and division, are similar to the properties of fractions.

Review Questions

• Explain how rational expressions can be used to model real-world situations involving rates, ratios, and proportions.
  • Rational expressions are useful for modeling real-world situations involving rates, ratios, and proportions because they represent a relationship between two quantities. For example, a rational expression could be used to model the rate of production in a manufacturing process, the ratio of male to female employees in a company, or the proportion of a mixture of two substances. The properties of rational expressions, such as simplifying and performing operations, allow for the analysis and optimization of these types of situations.
• Describe the process of simplifying a rational expression and explain why this is an important step in working with rational expressions.
  • Simplifying a rational expression involves factoring the numerator and denominator and then canceling any common factors. This is an important step because it reduces the expression to its simplest form, making it easier to perform further operations, such as addition, subtraction, multiplication, and division. Simplifying a rational expression also helps to reveal the underlying structure and relationships within the expression, which can be crucial for understanding the behavior of the expression and its applications.
• Analyze the role of partial fractions in working with rational expressions, particularly in the context of integration and other mathematical operations.
  • Partial fractions is a technique used to express a rational expression as a sum of simpler rational expressions. This is particularly useful in the context of integration, where the integral of a rational expression can often be more easily evaluated by first expressing the rational expression as a sum of partial fractions. The partial fractions technique can also be helpful in other mathematical operations, such as finding the roots of a rational expression or solving differential equations involving rational expressions. By breaking down a complex rational expression into a sum of simpler rational expressions, the partial fractions method can simplify the analysis and manipulation of the original expression.

Related terms

Polynomial: A polynomial is an algebraic expression that consists of variables and coefficients, where the variables are raised to non-negative integer powers.

Simplifying Rational Expressions: The process of reducing a rational expression to its simplest form by factoring the numerator and denominator and canceling common factors.

Partial Fractions: A technique used to express a rational expression as a sum of simpler rational expressions, which can be useful for integration and other mathematical operations.