Irrational Number
Real number that cannot be written in the form of the ratio [latex]\frac {a}{b}[/latex] where [latex]a[/latex] and [latex]b[/latex] are integers and [latex]b[/latex] ≠ 0.
Symbols
The symbol [latex]\mathbb{Q'}[/latex] represents the set of irrational numbers and is read as "Q prime". The symbol [latex]\mathbb{Q}[/latex] represents the set of rational numbers. Combining rational and irrational numbers gives the set of real numbers: [latex]\mathbb{Q}[/latex] U [latex]\mathbb{Q'}[/latex] = [latex]\mathbb{R}[/latex].Examples
The numbers [latex]\sqrt{5}[/latex], [latex]\sqrt{11}[/latex], [latex]\dfrac{\sqrt{5}}{7}[/latex], π and e are irrational numbers.- [latex]\sqrt{5}[/latex] = 2.236 067 ...
- [latex]\sqrt{11}[/latex] = 3.316 624 ...
- [latex]\dfrac{\sqrt{5}}{7}[/latex] = 0.319 438 ...
- π = 3.141 592 ...
- e = 2. 718 281 ...