Question

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

{(1, –1), (4, –2), (9, –3), (16, –4), (25, –5)}

{(1, 1), (2, 4), (3, 9), (4, 16), (5, 25)}

{(1, –1), (2, –2), (0, 0), (1, 1), (2, 2)}

{(–1, 1), (–2, 4), (–3, 9), (–4, 16), (–5, 25)}

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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