Which relation is a function?

A.
{(1, 2); (2, 3); (3, 4); (1, 5)}

B.
{(1, 2); (2, 5); (3, 2); (4, 5)}

C.
{(1, 2); (2, 3); (3, 4); (2, 5)}

D.
{(1, 2); (1, 3); (3, 2); (4, 2)}

Question

Which relation is a function?	
 
 A.
{(1, 2); (2, 3); (3, 4); (1, 5)}
 
 B.
{(1, 2); (2, 5); (3, 2); (4, 5)}
 
 C.
{(1, 2); (2, 3); (3, 4); (2, 5)}
 
 D.
{(1, 2); (1, 3); (3, 2); (4, 2)}

anonymous · Answer

@ganeshie8 @Destinymasha

anonymous · Answer

you can notice that the pattern in  A  is

1                         1   +1                       2    +1
--         -->      --------       -->    ----                ......
2                         2   +1                       3    +1

but the last point doesn't work according to the pattern, so it's therefore not a function.

In B it just has no pattern...

In C same pattern like A, and also, the last point is not according to the pattern, but, the only difference is that in A it's (1,5) and in C it's (2,5)..

D doesn't have the same type of pattern either.


NONE of them are linear function....

perhaps they are absolute value functions or exponential.. I'll check....

anonymous · Answer

SO its either A or C

anonymous · Answer

graphing the points for A https://www.desmos.com/calculator/zkp3hbgzrf graphing the points for B https://www.desmos.com/calculator/b8xznq57k8 graphing the points for C https://www.desmos.com/calculator/4hxeclwzoe graphing the points for D https://www.desmos.com/calculator/ljjfvotnbo

anonymous · Answer

Therefor the answer is...

anonymous · Answer

it looks like it's not A...
B is a parallelogram (so I think it is the correct choice - a function)
C .... I would think it's not a function.
D for sure not...

anonymous · Answer

My best would be B, but I don't swear that it's correct.