## samtab 2 years ago 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:(

1. xxCyndi

look at the x value of each point.

2. xxCyndi

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 :)

3. samtab

does that mean its d?

4. xxCyndi

no

5. xxCyndi

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

6. samtab

im sorry but i dont get it

7. xxCyndi

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

8. xxCyndi

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)

9. samtab

so its a?

10. xxCyndi

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.

11. xxCyndi

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

12. samtab

what>

13. xxCyndi

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

14. samtab

no

15. xxCyndi

you see the numbers in the parenthesis?

16. samtab

yeah

17. xxCyndi

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.

18. xxCyndi

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.

19. xxCyndi

{(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.

20. xxCyndi

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.

21. samtab

thanks;)

22. xxCyndi

npnp :)