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What is the difference between real numbers and irrational numbers?

Published in Mathematics 1 min read

Real Numbers

Real numbers encompass all numbers that can be plotted on a number line. This includes both rational and irrational numbers.

Irrational Numbers

Irrational numbers are a subset of real numbers. They cannot be expressed as a simple fraction, meaning they cannot be written as a ratio of two integers. They have decimal representations that are non-terminating and non-repeating.

Key Differences:

  • Rational Numbers: Can be expressed as a fraction of two integers (e.g., 1/2, 3/4, -5/7). Their decimal representations either terminate (e.g., 0.5) or repeat (e.g., 0.333...).
  • Irrational Numbers: Cannot be expressed as a fraction of two integers. Their decimal representations are non-terminating and non-repeating (e.g., pi (π) = 3.14159265..., √2 = 1.41421356...).

Examples:

  • Rational: 2, -3, 0.75, 1/3
  • Irrational: π, √2, √3, e

In Summary:

All irrational numbers are real numbers, but not all real numbers are irrational. Irrational numbers have decimal representations that are non-terminating and non-repeating, while rational numbers can be expressed as a fraction of two integers.

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