[tex]\bf \stackrel{\textit{range is always the set of y-coordinates}}{f=\{(2,\stackrel{\downarrow }{3}),(5,\stackrel{\downarrow }{7}),(3,\stackrel{\downarrow }{3}),(5,\stackrel{\downarrow }{4}),(9,\stackrel{\downarrow }{1})\}}\qquad \qquad \{3,7,3,4,1\}\implies \{3,7,4,1\}[/tex]