Question

Which relation defined by a set of ordered pairs is not a function?

Answer 1

The answer is:  [C]:  
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"{(1, –1), (2, –2), (0, 0), (1, 1), (2, 2)} " {(1, –1), (2, –2), (0, 0), (1, 1), (2, 2)}" .
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This set of ordered pairs is NOT a function because their is one x-coordinate in this set that has multiple y-coordinates;  
                               specifically:  "(1, -1)" ; and "(1, 1)".
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       All of the other answer choices given are functions.
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