Question

Can some explains this to meh. please?

Answer 1

Look at these sets of ordered pairs.
W) {(8, 9), (2, 3), (0, -2), (10, -9)}
X) {(0, 0), (5, 10), (-3, 3)}
Y) {(1, 1), (2, 2), (3, 3), (4, 4)}
Z) {(-10, 1), (-9, 3), (-4, 5)}
Which of the sets represent functions?

Answer 2

W is a function because each of the x values (first values in each pair) has a different value of y associated with it

Answer 3

Z is also a function for the same reason

Answer 4

so what you are saying is that w and z are functions because x and y do not have the same values

Answer 5

Y maps on to itself - not sure but i think a function can do that.

Answer 6

hmmm

Answer 7

i hate to disgree with @welshfella but this is what you need to look at:
if all the x values are distinct (all different) then it IS a function
if there are repeated x values (some are the same) then it is NOT a function

Answer 8

ignore the y values completely
they have nothing whatsoever to do with it

Answer 9

no
a relation is a function if each value of x only maps on to a single value of y

so a function can be one-to-one or many=to-one but it cant be one-to-many

Answer 10

\[W) \{(\color{red}8, 9), (\color{red}2, 3), (\color{red}0, -2), (\color{red}{10}, -9)\}\]

Answer 11

all x's are different, it IS a function

Answer 12

so {(3,1) (2,3) is a function but {(3,1) (3,4) is not a function (as its one-to-many)

Answer 13

so which values do i compare to tell if one value is a function itself

Answer 14

This is not my expertise but aren't they all functions?

Answer 15

so W,Y, and Z are the functions or is it all of them

Answer 16

yes you are right misty - my error

Answer 17

I think all of them are

Answer 18

I am sorry i am confused which ones are the functions and which ones are not?

Answer 19

all are

Answer 20

okay thank you @welshfella and thank you as well @misty1212

Answer 21

just check out the x values as misty said - they are all different in each function

Answer 22

I have trouble with functions on times.....

Answer 23

- you can have repetition of y values but not of x values

so { (1,2), (2,2) } for example is a function because its many-to-one