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20 POINTS FOR YOUR TIME! PLEASE HELP!! Which relation is a function? A. {(1, −7), (2, −8), (−2, 7), (1, 8)} **
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Question

20 POINTS FOR YOUR TIME! PLEASE HELP!!

Which relation is a function?

A. {(1, −7), (2, −8), (−2, 7), (1, 8)}

B. {(−2, 2), (−7, 7), (−1, 1), (−8, 8)}

C. {(−2, 1), (−7, −1), (2, 8), (−7, −8)}

D. {(−2, 1), (−2, 2), (−2, 7), (−2, 8)}

Please provide evidence/proof on how you got the answer! Thank you!!!

## Answers ( No )

For a relation to be function, every x value should have its unique image in co-domain. If x is related to more than one y value, then that relation is not a function

In 1, as you can see, 1 related to -7 as well as 8. Which means 1 has two images viz. -7 and 8. But for a relation to be function, x should have only one image. Thus, it is not a function.

The worst is the 4th one in which -2 has 4 images.

Therefore, only relation B is a function.