Question

Which of these is a function?


{(0, 4), (0, 5), (0, 9), (0, 23)}
{(0, 1), (1, 2), (1, 5), (2, 9)}
{(0, 4), (2, 4), (3, 7), (4, 9)}
{(6, 0), (6, 1), (6, 7), (6, 11)

please help me:(

Answer 1

look at the x value of each point.

Answer 2

it's consider a function if x-value is not repeated,
it's not consider a function if the x-value is repeated.
hope this helps :)

Answer 3

does that mean its d?

Answer 4

no

Answer 5

look at option d, the domain are repeated. since it's all 6's.
look for the option that the domains are different numbers.
domain=xvalue

Answer 6

im sorry but i dont get it

Answer 7

you see the ( )
and the number within it right?
sorry i'm bad at explaining
in the ( ) you have whats called the x value and the y value

Answer 8

put it simply example (1,9) the first number 1, would be your x value, and the 9 would be your y value. hence, (x,y)

Answer 9

so its a?

Answer 10

a (0,4) (0,5) (0,9) (0,23)
you see how it is all 0's?
that means domain is repeated since 0 is repeated.

Answer 11

it is not a, to answer your question. look at the first number, your x value. remember it cannot be repeated.

Answer 12

what>

Answer 13

do you know, what are x values and y values？

Answer 14

no

Answer 15

you see the numbers in the parenthesis?

Answer 16

yeah

Answer 17

the first number would be you x value/domain
let's take your question for example
take your first parenthesis on a for example.
you have (0,4)
correct?
like i mention earlier, the first number is your x-value, which by looking at the number in the parenthesis you have 0.
so your x value, which is also your domain, is 0.

Answer 18

now, you look at every single parenthesis in option a.
remember that first number is always your x-value
and the definition for a function is that x-value(domain) cannot be repeated.
{(0, 4), (0, 5), (0, 9), (0, 23)}
see how the domain is repeated since the first number is all 0's?
which would make option a NOT a function.

Answer 19

{(0, 1), (1, 2), (1, 5), (2, 9)}

looking at the option B.
for option B, you have x value of : 0,1,1,2
see how 1 is repeated in this function? so therefore, B is NOT a function as well.

Answer 20

the correct answer would be c.

{(0, 4), (2, 4), (3, 7), (4, 9)}
looking at the first number of the parenthesis
you would get the x value of:
0,2,3,4
you see how the number above is not repeated?
that means this is the correct answer because it would represent a function.

Answer 21

thanks;)

Answer 22

npnp :)