Explanation:
A relation is a function if every value of x is related to just one value of y.
So, number 6 is not a function because -4 is related to 9 and -4 is also related to 0.
Number 7 is a function because every value of x (first coordinate) is related to one value of y (second coordinate).
In the same way, we can say that number 8 is also a function and number 9 is not a function because number 7 is related to 0, -5, -8, 4, and 3.
Finally, for the graph of numbers 10, 11, and 12 we need to identify the coordinates of every point.
So, number 10 is equivalent to:
{(-7, -1), (-2, -7), (0, 2), (4, 2), (6,6)}
It means that number 10 is a function
For number 11, we get:
{(-5, -4), (-3, 5), (2, -1), (2
