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