Number that, when written in decimal notation, is an unlimited decimal sequence periodic or not.
Notations
- The symbol that represents the set of real numbers is the letter \(\mathbb{R}\).
- The symbol that represents the set of real positive numbers is: \(\mathbb{R}_{+}\) = {x ∈ \(\mathbb{R}\) | x ≥ 0}
- The symbol that represents the set of real negative numbers is:\(\mathbb{R}_{–}\) = {x ∈ \(\mathbb{R}\) | x ≤ 0}
- The symbol that represents the set of the non-zero real numbers is: \(\mathbb{R}{^*}\) = {x ∈ \(\mathbb{R}\) | x ≠ 0}
- The symbol that represents the set of strictly positive real numbers is: \(\mathbb{R}_{+}^{*}\) = {x ∈ \(\mathbb{R}\) | x > 0}
- The symbol that represents the set of strictly negative real numbers is: \(\mathbb{R}_{–}^{*}\) = {x ∈ \(\mathbb{R}\) | x < 0}
The set \(\mathbb{R}\) of real numbers appears in this Venn diagram:
