Function:
A relation is a function if each input (x value) has a different output (y value).
If an input has two different output values then it is not a function.
Question 6:
We are given the (x, y) ordered pairs.
x is the input value and y is the output value.
As you can see, the input (-4) has two different output values (9 and 0)
Therefore, it is not a function.
NO
Question 7:
We are given the (x, y) ordered pairs.
As you can see, each input has a single output.
Therefore, it is a function.
YES
Question 8:
This time we are given a table of x, y values.
The same logic applies here too.
As you can see, each input has a single output.
Therefore, it is a function.
YES
Question 9: