recall that in a function, the output or f(x) or namely the dependent variable set is the range.
[tex]\bf \begin{array}{ccll} \stackrel{domain}{x}&\stackrel{range}{y}\\ \cline{1-2} 2&4\\ 3&3\\ 4&2 \end{array}\qquad \qquad \stackrel{\mathbb{RANGE}}{\{4,3,2\}}[/tex]