Question

Determine which of the following representations model function relationships.
I know B is a function, but I'm not sure about A,C, and D.

Answer 1

@Hero

Answer 2

Are you familiar with the Vertical Line Test? That's one method you can use to determine if the graph of a relation is a function.

Answer 3

Yes I am familiar with it, I was just looking at A and think it is a function because the x-values don't repeat.

Answer 4

but I don't know how to solve C and D

Answer 5

Yes, A is also a function. So we know A and B are functions because they pass the vertical line test. For C, we have to make a graph.

Answer 6

One moment...

Answer 7

Okay, so like, (1,1) (1,1) (1,2)? then plot it on the graph?

Answer 8

Yes, exactly

Answer 9

okay I don't think its a function because the x-value repeats 3 times.

Answer 10

Works out to something like that. One of the students gets two cups of hot chocolate, probably by accident or because they're the favored student, so it works out to not being a function.

Answer 11

For D, we can graph that relation using Geogebra to figure out if it is a function or not.

Answer 12

okay

Answer 13

If you go to http://www.geogebra.org/classic you can graph it yourself

Answer 14

What does the line under the plus sign mean? do I have to do something different with the equation?

Answer 15

It means there are two graphs of the square root function except one is positive and the other is negative.

Answer 16

oh okay, is this going to change the way I write it out?

Answer 17

like do I still say \[y=+\sqrt{x}\]

Answer 18

oh okay, so doing the vertical line test it doesn't pass so its not a function.

Answer 19

Correct

Answer 20

Thank you so much

Answer 21

You're welcome.