Question

which relation is a function?

{(1,2),(2,3),(3,4),(2,5)}

{(1,2),(2,3),(3,4),(1,5)}

{(1,2),(1,3),(3,2),(4,2)}

{(1,2),(2,5),(3,2),(4,5)}

Answer 1

someone please help me

Answer 2

@retirEED

Answer 3

I can't see one right off.

I need to plot them. I suggest you try the same thing!

Answer 4

ok @retirEED

Answer 5

i think its the last one

Answer 6

let's take a peek at the first one

keep in mind that, a function is one that doesn't have any X-REPEATS
that is, one that doesn't have the same ordinal value in the pair

lemme show that on the first one, hold the mayo

Answer 7

ok @jdoe0001

Answer 8

well. notice the first choice given \(\large \{({\color{brown}{ 1}},2),({\color{brown}{ 2}},3),({\color{brown}{ 3}},4),({\color{brown}{ 2}},5)\}\)

do you see any REPEATS or repeated 1st value in the pairs?

Answer 9

yes 2

Answer 10

ahha! then is NOT a function :)

the function willl have, no repeated 1st value, that is, no X-REPEATS :)

Answer 11

yea i got the track of this now

Answer 12

so its the last one

Answer 13

because it doesn't have any repeats

Answer 14

yeap
the last one's DOMAIN is 1,2,3,4 <-- no repeats, thus, is a function

Answer 15

you deserve a medal!

Answer 16

Yes he does. I was looking fora a function like a line or a parabola.

Answer 17

I need to go back to the basic definition!