Real Number
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 [latex]\mathbb{R}[/latex].
- The symbol that represents the set of real positive numbers is: [latex]\mathbb{R}_{+}[/latex] = {x ∈ [latex]\mathbb{R}[/latex] | x ≥ 0}
- The symbol that represents the set of real negative numbers is:[latex]\mathbb{R}_{–}[/latex] = {x ∈ [latex]\mathbb{R}[/latex] | x ≤ 0}
- The symbol that represents the set of the non-zero real numbers is: [latex]\mathbb{R}{^*}[/latex] = {x ∈ [latex]\mathbb{R}[/latex] | x ≠ 0}
- The symbol that represents the set of strictly positive real numbers is: [latex]\mathbb{R}_{+}^{*}[/latex] = {x ∈ [latex]\mathbb{R}[/latex] | x > 0}
- The symbol that represents the set of strictly negative real numbers is: [latex]\mathbb{R}_{–}^{*}[/latex] = {x ∈ [latex]\mathbb{R}[/latex] | x < 0}
The set [latex]\mathbb{R}[/latex] of real numbers appears in this Venn diagram:
