Question

Which of the following relations could be a function? Select all that apply.O {(1,5), (3, 6), (5, 9)}O {(1, 1), (1, 2), (1, 3)}{(5,2), (3, 6), (5, 8)}{(8,3), (6, -1), (2, 0)}O {(-1,5), (9, 4), (2,-3)}

Answer 1

Given a set of ordered pairs, to find the set tha represent a function, we have to look at the x coordinates. If there are points with repeated x coordinates, then, that set does not represent a function. For example, the sets:

$\begin{gathered} \mleft\lbrace(1,1\mright),(1,2),(1,3)\} \\ \mleft\lbrace(5,2\mright),(3,6),(5,8)\} \end{gathered}$

cannot represent a function, while the following sets:

$\begin{gathered} \mleft\lbrace1,5\mright),(3,6),(5,9)\} \\ \mleft\lbrace(8,3\mright),(6,-1),(2,0)\} \\ \mleft\lbrace(-1,5\mright),(9,4),(2,-3)\} \end{gathered}$

can represent a function