Question

Which explains why the graph is not a function

Answer 1

There are 2 blue Dots on X4 at different Y values.

In order for it to be a function, you can only have one output ( Y value) for each input (X value).

The last answer is correct: it is not a function because there are two different Y values for a single X value.

Answer 2

Remember when you got that question in math about an input-output table, saying that this couldn't happen?

x     y

1+1 =1

2+1=2

3+1=4

3+1=5

4+1=5

5+1=6

That's because two y values cannot be obtained by the same x-value. On the graph, graphically it shows this when there are two points (4,4) and (4,-2). This cannot happen.

The answer that you're looking for is the last answer choice. Great question!