Irrational Numbers

Definition

Irrational numbers are real numbers that cannot be expressed as a simple fraction of two integers. They have decimal expansions that never repeat or terminate, continuing on forever in a non-repeating, non-terminating pattern.

5 Must Know Facts For Your Next Test

1. Irrational numbers cannot be expressed as a simple fraction, and their decimal representations never repeat or terminate.
2. Common examples of irrational numbers include $\pi$ (pi), $\sqrt{2}$, $\sqrt{3}$, and $e$ (the base of natural logarithms).
3. Irrational numbers are essential in the study of geometry, trigonometry, and calculus, as they arise in the measurement of circles, triangles, and other shapes.
4. Simplifying expressions with irrational numbers, such as square roots, often involves using the properties of real numbers and the laws of exponents.
5. Irrational numbers have important applications in fields like physics, engineering, and computer science, where precise measurements and calculations are crucial.

Review Questions

• Explain how irrational numbers differ from rational numbers and provide examples of each.
  • Rational numbers are numbers that can be expressed as a ratio of two integers, with the denominator not equal to zero. These include fractions, whole numbers, and repeating or terminating decimal numbers. In contrast, irrational numbers cannot be expressed as a simple fraction and have decimal expansions that never repeat or terminate. Examples of irrational numbers include $\pi$, $\sqrt{2}$, and $\sqrt{3}$, which have non-repeating, non-terminating decimal representations.
• Describe the role of irrational numbers in the context of the properties of real numbers.
  • Irrational numbers, along with rational numbers, make up the set of real numbers. The properties of real numbers, such as the commutative, associative, and distributive properties, apply to both rational and irrational numbers. Additionally, irrational numbers are essential in understanding concepts like the measurement of circles, triangles, and other geometric shapes, as well as in the study of trigonometry and calculus, where precise calculations involving irrational values are required.
• Analyze the importance of simplifying expressions with irrational numbers, such as square roots, and explain how this relates to the topics of integers, decimals, and the properties of real numbers.
  • Simplifying expressions with irrational numbers, particularly square roots, is crucial in the study of intermediate algebra. This skill requires understanding the properties of real numbers, including the laws of exponents, to manipulate and evaluate expressions involving irrational values. The connection to integers and decimals arises when working with irrational numbers, as they cannot be expressed as simple fractions and have non-repeating, non-terminating decimal representations. Mastering the simplification of expressions with irrational numbers, such as $\sqrt{16}$ or $\sqrt{3} + \sqrt{2}$, demonstrates a deep understanding of the properties of real numbers and how they apply to both rational and irrational values.

Related terms

Real Numbers: The set of all numbers, including rational numbers (fractions) and irrational numbers.

Rational Numbers: Numbers that can be expressed as a ratio of two integers, with the denominator not equal to zero.

Square Root: The inverse operation of squaring a number, used to find irrational numbers like $\sqrt{2}$ and $\sqrt{3}$.