Greatest common divisor
From Maths
Note: requires knowledge of what it means for a number to be a divisor of another.
Definition
Given two positive integers, [ilmath]a,b\in\mathbb{N}_+[/ilmath], the greatest common divisor of [ilmath]a[/ilmath] and [ilmath]b[/ilmath][1] is the greatest positive integer, [ilmath]d[/ilmath], that divides both [ilmath]a[/ilmath] and [ilmath]b[/ilmath]. We write:
- [ilmath]d=\text{gcd}(a,b)[/ilmath]
Terminology
Co-prime
If for [ilmath]a,b\in\mathbb{N}_+[/ilmath] we have [ilmath]\text{gcd}(a,b)=1[/ilmath] then [ilmath]a[/ilmath] and [ilmath]b[/ilmath] are said to be co-prime[1]
