Question

1. Label each representation below as a "Function" or "Not a function".

a.
b.
o.
х
у
{(-2,9), (0, -4), (3, 12), (1, 1))
-1
1
-1
2
-1
3
-1
4
Function
not a function
not a function

Answer 1

a. Function

b. Function

c. Not a function

Explanation:

Here is a basic rule to determine if a relation is a function of not:

1. A function has only one exact y-value (range) assigned to each x-value (domain).

2. A x-coordinate value is not repeated in a function, however, a y-coordinate value can be repeated. This means, the same y-value can be assigned to different x-values.

Bearing these in mind, let's label the given representation accordingly:

a. There is exactly one y-value assigned to each x-value, and also, no x-value is repeated. Therefore, it is a function.

b. The graph shows a repeating y-value, however, each x-value has exactly one y-value assigned to it. Therefore the graph represented is a function.

c. The table shows a repeating x-values. This is definitely not a function.