Question

Which of the sets of ordered pairs represents a function?

P = {(3, 5), (–1, 5), (4, –6), (2, 9)}

Q = {(7, –2), (5, 9), (–1, 8), (5, –3)}
Only P
Only Q
Both P and Q
Neither P nor Q

Answer 1

If you were to draw a graph, you would do a vertical line test on the graph to figure out if it is a function

The vertical line test is where if you draw a vertical line, it won't cross 2 points. This is to say, that for any y value, you get a unique x value

so looking at

P={(3,5), (-1,5), (4,-6), (2,9)}

Do any y values share an x value?
Please note that a coordinate is written as (x,y), so (3,5) means x=3, y=5

Answer 2

this is a function since all x values map to one y value

this is not a function since x values map to 2 y values