Question

quesiong in coments

Answer 1

@koook

Answer 2

@jim_thompson5910

Answer 3

You know it's not a function if you can draw a straight line through the two points. If they intersect then you can rule out that it's not a function.

Answer 4

So we know it's not A because we can draw a straight line down through y=2 and y=-2. We know it's not B because we can draw a straight line down through y=1 and y=-2

Answer 5

So essential you can also think of it as:

There is only one output for every input otherwise not a function.

Answer 6

so is it C ?

Answer 7

What is y and x = -1?

Answer 8

There are two correct answers the question i asked.