Set of numbers whose decimal notation is an infinite decimal sequence that may or may not be periodic.
Symbol
The set of rational numbers is denoted by the symbol \(\mathbb{R}\).
- The set of positive real numbers : \(\mathbb{R}\)\(_{+}\) = {x ∈ \(\mathbb{R}\) | x ≥ 0}
- The set of negative real numbers : \(\mathbb{R}\)\(_{–}\) = {x ∈ \(\mathbb{R}\) | x ≤ 0}
- The set of strictly positive real numbers : \(\mathbb{R}\)\(_{+}^{*}\) = {x ∈ \(\mathbb{R}\) | x > 0}
- The set of strictly negative real numbers : \(\mathbb{R}\)\(_{–}^{*}\) = {x ∈ \(\mathbb{R}\) | x < 0}
All whole numbers, integers, decimals and rational numbers are real numbers.