Answer: Choice C
Domain: {-1, 1, 4}
Range: {-4, 3, 4}
Not a function
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Explanation:
The domain is the set of allowed x inputs, while the range is the set of allowed y outputs.
To form the domain, we simply list the x coordinates of each point. Toss any duplicates. The range is the same story, but with the y coordinates.
We do not have a function because x = 4 repeats itself. The input x = 4 leads to multiple outputs.
Side note: it's optional to sort each set.
