kaylalynn 2 years ago which is a function?

1. kaylalynn

$A. \left[ y \right]$

2. ParthKohli

The guy which has a unique mapping to it.

3. Speedy_Jazz

do you have a better example?

4. Dean.Shyy

This may help: http://is.gd/PItqZG

5. Speedy_Jazz

That does help Dean,shy

6. kaylalynn

$A. x=\left[ y \right]$ $B. y= \left| x \right|$ $C. x ^{2} + y ^{2} = 49$ $D. x = y ^{2}$

7. nincompoop

8. kaylalynn

which ever one is a function. . .

9. nincompoop

which do you think IS a function in the choices you've been provided?

10. kaylalynn

D?

11. nincompoop

why?

12. kaylalynn

because it has a y. lol im so sorry. im tired!!

13. nincompoop

hehehe I don't think you read the attachment that was shared to you. read it a little bit, will you? it will help you answer a lot of problems regarding functions

14. kaylalynn

C?

15. nincompoop

okay, you're just obviously guessing. did you read the attachment?

16. kaylalynn

i did. but none of them look like that. or else i would have known it at first.

17. nincompoop

so what do you understand about function?

18. nincompoop

by the way, do you understand the [ ] and | | in A and B respectively?

19. kaylalynn

i understand the absolute value signs but i dont know what the bracket things are

20. nincompoop

brackets and curly braces are used when there are nested parentheses to avoid confusion –{2x – [3 – (4 – 3x)] + 6x}

21. kaylalynn

so it would be B because the graph of y = |x| passes the vertical line test??

22. nincompoop

so your A is just simply x = y, which is y = x now if you read the attachment, this could mean f(x) = x

23. kaylalynn

ok so it could mean f(x) = x?

24. nincompoop

yes, it means that the output is the same as the input f(x) the x inside the parenthesis, gives an output of x f(x) = x f(2) = 2 f(blah) = blah

25. kaylalynn

oh ok. that makes sense now!

26. kaylalynn

thanks! i apologize! Im soo tired!

27. nincompoop

will it pass the vertical or horizontal line test?

28. kaylalynn

if x = 2 or 3 or 4 etc. it will pass the vertical line test which means it is a function. But it will not pass the horizontal line test which means it is not a 1 - 1 function.

29. kaylalynn

right?

30. kaylalynn

sorry i meant y

31. kaylalynn

x does not pass the vertical line test so it is not a function

32. nincompoop

input x | output y ------------------ 1 | 1 3 | 3 5 | 5 it is a 1 to 1 no matter what |dw:1365917751738:dw|

33. Directrix

>> which is a function? @kaylalynn A function f is the set of ordered pairs (x,y) such that if (x1, y1) AND (x1,y2) are elements of f, then y1 = y2.