What’s the answer

Question

Which set of ordered pairs represents a function?

O {(7,4),(3,8), (-4,-4), (0,4)}

O {(-8,0), (-5,6), (-8,1),(-6,5)}

O {(-5, 1), (3, –7), (2, -4), (2,7)}

O {(4,2), (4, -9), (-9,-6), (7,1)}

Answer 1

the first is the only function

the last 3 have two points where one x value has 2 y values. If you plot them you can draw a vertical line which intersects both points. A function means you cannot draw a vertical line through the graph that cuts the graph in more than one point.