Question

Is this a function ?

{ (-3,-6) , (-1,-6) , (5,-6) , (8,-6) }

Answer 1

your y values are all same, and x values are the ones that differ.
That means it is a horizontal line.

Answer 2

Is horizontal line a function?

Answer 3

yes ? Isn't any straight line a function ?

Answer 4

Yes, it is a function.
No a vertical line is not a function.

Answer 5

Well, it is not an explicit function.

Answer 6

(Also, vertical line has no slope. )

Answer 7

THX !

Answer 8

yw

Answer 9

http://www.mathsisfun.com/sets/function.html
I love Google

Answer 10

me too ^_^

Answer 11

i think it is a missing a couple of things, but isn't a bad source.

Answer 12

As far as a relation goes in your case (which is called a "discrete" function, since it is just a set of points that aren't connected together on the graph), for it to be a function, you just need the x-values not to repeat more than 1s.

Answer 13

As regards to other functions (those that are connected as a graph, as opposed to a set of points).
For a function to be explicit, you also have to not have the same x value more than once.

For a function to be "one to one" your y values and your x values shouldn't repeat more than once.