A OR D??
Which of the sets of ordered pairs represents a function?

A = {(1, −2), (3, −5), (5, 2), (7, 5)}

B = {(4, 2), (4, −2), (9, 3), (9, −3)}

Only A
Only B
Both A and B
Neither A nor B

Question

A OR D??
Which of the sets of ordered pairs represents a function? 

A = {(1, −2), (3, −5), (5, 2), (7, 5)} 

B = {(4, 2), (4, −2), (9, 3), (9, −3)}

 Only A
 Only B
 Both A and B
 Neither A nor B

milo123 · Answer

@EclipsedStar

milo123 · Answer

@ShadowLegendX

zzr0ck3r · Answer

if there are no repeated x values then it is a function

itrymath · Answer

A

zzr0ck3r · Answer

dont give answer @ItryMath we are here to help

itrymath · Answer

Because if the "x" aka Domain is repeated more than once it is a invalid function

itrymath · Answer

who said i was not going to explain @zzr0ck3r  ;)

milo123 · Answer

but 2 and 5 appear more than once itrymath

shadowlegendx · Answer

VLT, or Vertical Line Test

|dw:1479452695163:dw|

Two points, at different elevations on the y axis, at the same spot on the x axis(same x coord, different y coord), means it is not a function and has failed the VLT

itrymath · Answer

If range has the same number as does the domain then it doesn't matter unless domain is repeated

itrymath · Answer

If the range is repeated it doesn't matter

itrymath · Answer

Or use the shadow designed

itrymath · Answer

Any questions ?

cazeh · Answer

A = {(1, −2), (3, −5), (5, 2), (7, 5)}

cazeh · Answer

i got it on my assessment.

whpalmer4 · Answer

actually, repeated $x$ values are fine in such a relationship, so long as they always have the same value of $y$ associated with them.  However, having any value of $x$ associated with multiple values of $y$ means it is not a function.  A function maps a unique value of $y$ to each value of $x$. 

@zzr0ck3r

kidcuddi · Answer

do you still need help?

jalil.h · Answer

please close this question if your finished getting help

zzr0ck3r · Answer

@whpalmer4 thanks..... They normally don't add repeated pairs, as the set $\{a,a\}$ is the same as the set $\{a\}$. I used to explain that part, but it sounds confusing it writeing to most people and often does not aply.

whpalmer4 · Answer

I agree that there is no need to have repeated pairs, but I often see such problems posted on OpenStudy which do in fact have repeated pairs, so just saying "repeated x value -> not a function" may lead them astray, and does not contribute to really understanding the concept, in my opinion.