Question 45027
R is not a function because points (1, 2) and (1, 0) both have the same value for x.  Therefore, the x's and y's do not have a one-to-one relationship.
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b) Point (0,-4) lies on the y-axis.
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c) (-3, 4)
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d)
x: 1 , -3 , 0 , 1
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y: 2 , 4 , -4 , 0)