[tex]\bf \begin{array}{llll}
&[(-6,2),(2,3),(1,1),(-7,2),(4,2)]\\\\
inverse& [(2,-6),(3,2),(1,1),(2,-7),(2,4)]
\end{array}
\\\\\\
\textit{is the original a one-to-one?}\qquad \stackrel{rep eated~y-values}{(-6,\stackrel{\downarrow }{2}),(2,3),(1,1),(-7,\stackrel{\downarrow }{2}),(4,\stackrel{\downarrow }{2})}[/tex]
notice, the inverse set is just, the same set with the x,y turned to y,x, backwards.
is it a one-to-one? well, for a set to be a one-to-one, it must not have any x-repeats, that is, the value of the first in the pairs must not repeat, and it also must not have any y-repeats, namely the value of the second in the pairs must not repeat.
