Question

Which relation is a function?

Answer 1

Hi there!  

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I believe your answer is:  

D) {(1, 2), (2,4), (−1, 2), (0,3)}

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Here’s why:  

• A function is a relation in which one element of the domain is assigned to exactly one element of the range.
• This means that the domain (x) values must not repeat.

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Option A's answer is incorrect, as the domain value of '5' repeats.

{(5, 0), (0, 1), (5, 2), (4,4)}  

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Option B is not a function due to the repeating '-4' value.

{(0, 1), (−4, 1), (4, 2), (−4,−1)}

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The '3' in option C's given relation repeats.

{(3, 2), (2,1), (−1, 2), (3,3)}

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Option D is the correct answer, as there are no domain values that repeat.  

{(1, 2), (2,4), (−1, 2), (0,3)}

Therefore, option D is a function.

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Hope this helps you. I apologize if it’s incorrect.