Question

ill medal!
Please just tell me how to do it :)
Which relation is a function?

A.
(–8, –3), (–1, –5), (–8, –2)

B.
(1, –3), (5, –3), (–3, 7)

C.
(–3, 0), (5, 9), (–3, 2)

D.
(1, 2), (1, 1), (0, 1)

Answer 1

Functions defined as f(x) which means for any single value of a parameter x you get single value of the function f(x). So as you look at this set of pair, the ones where you find same x having multiple different resulting f(x) is the ones that do not satisfy that criteria.

Answer 2

Wait.
Wut?

Answer 3

TL;DR: Functions only have one y-value for a particular x-values.

Answer 4

So a pair like this: (8,7) is a function?

Answer 5

Yes (8,7) is a function, when you "plug" in 8 into your function you get 7 as your y output. You can only \(\ \sf have~one\) corresponding y value for \(\ \sf each\) x input.

Answer 6

correction: a particular x-value**

Answer 7

"each" is interpreted as particular.

Answer 8

Oh ok.
So If you line up all the X values and all the Y values, the all have to math up to make it a relation?
So that it looks like this?
X= 6,7,8
Y=3,4,5
And NOT like this?
X=4,5,6,7
Y=1,2
Correct?

Answer 9

I meant match up XD

Answer 10

._. You're missing 2 more values, what do you get when you plug in 6 and 7?

A function is something like this:

x | y
1 | 2
2 | 4
3 | 6

One that doesn't work is:

x | y
1 | 3
2 | 9
3 | 3

I can only get 3 if I plug in 1, I can only get 9 once when i plug in 2 etc.

http://www.purplemath.com/modules/fcns.htm

Answer 11

@tHe_FiZiCx99
I intentionally didnt put the two values cause I wanted to make sure that it wasnt a function.
Like, I was asking if they all match up evenly its a function, and if they dont, its not.

Answer 12

Oh!