The Real Number System

The Real Number System

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We use the following definitions:

  • \(\mathbb{N}\): natural numbers are \(\{1; 2; 3; \ldots\}\)

  • \(\mathbb{N}_0\): whole numbers are \(\{0; 1; 2; 3; \ldots\}\)

  • \(\mathbb{Z}\): integers are \(\{\ldots; -3; -2; -1; 0; 1; 2; 3; \ldots\}\)

The following video shows an example of determining which of the above sets of numbers a particular number is in.

Fact:

Not all numbers are real numbers. The square root of a negative number is called a non-real or imaginary number. For example \(\sqrt{-1}\), \(\sqrt{-28}\) and \(\sqrt{-5}\) are all non-real numbers.

This lesson is part of:

Algebraic Expressions Overview

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