Question

1.) Which relation is a function?

A {(–3, 4), (–2, 5), (0, 9), (0, 12)}
B. {(8, –1), (2, –1), (3, 8), (2, 5}
C. {(7, 12), (1, –5), (3, –10), (2, –5)}
D. {(1, 2), (1, 5), (1, –1), (1, 4)}

2.)which relation is a function?

Answer 1

1) A function won't have repeats of the x values . Thus the first choice will not be a function because of the 2 '0' x values.
C is the answer to thid question

2) The first choice A is the only function. It is the only one which passes the vertical line test. ( if we can draw any vertical line which passes through more than one point on the graph then its is NOT a function).