Question

Is y=x^2+4 a function? How do you know?

Answer 1

Of course it's a function!

Answer 2

If it passes the vertical line test, it's a function.

Answer 3

Vertical line test?

Answer 4

I checked the answer key, and it's not a function..

Answer 5

Have you checked the definition of a "function"?

Answer 6

yes

Answer 7

What does does it say?

Answer 8

A function is a special relationship between values: Each of its input values gives back exactly one output value.

Answer 9

Set up a table of values like ...-3, -2, -1, 0, 1, 2, 3, .. and test it.

Answer 10

How does that let me know whether it's a function or not?

Answer 11

buuurn!

Answer 12

lol, it's just a question

Answer 13

Does each input value give "back exactly one output value."???

Answer 14

Oh, I understand now! Thanks :)

Answer 15

But, won't I have to try out all of the numbers? What if somewhere along the line, the x has more than one y value?

Answer 16

are you sure you haven't entered the equation incorrectly

perhaps it should be

\[x= y^2 + 4\]

Answer 17

No, that is incorrect. The y value is always the output.

Answer 18

BUUUUUURN!!!!

Answer 19

omg it's just a correctionnn

Answer 20

no its a graph that looks like