Using Mathematical Conventions

Want some basic practice with variables first? Introduction to Variables

Recall:

$\mathbb{R}\,$ is the set of real numbers:   $\mathbb{R} = (-\infty,\infty)$

$\mathbb{Z}\,$ is the set of integers:   $\mathbb{Z} = \{\ldots,-3,-2,-1,0,1,2,3,\ldots\}$

Numbers are usually represented by lowercase letters, like $\,a\,$, $\,n\,$, or $\,x\,$.

Sets are usually represented by uppercase letters, like $\,A\,$, $\,B\,$, or $\,S\,$.

A variable with universal set $\mathbb{R}\,$ (or, any interval of real numbers) is most likely to be named with a lowercase letter from the end of the alphabet; particularly $\,t\,$, $\,x\,$, or $\,y\,$.

A variable with universal set $\mathbb{Z}\,$ (or, any subset of the integers) is most likely to be named with a lowercase letter near the middle of the alphabet; particularly $\,i\,$, $\,j\,$, $\,k\,$, $\,m\,$, or $\,n\,$.

Examples

Practice