Can't figure this out...?

Question

1. Given A = (-2, -1, 0, 1) and B = (1, 2, 3), determine which of the sets of ordered pairs represents a function from A to B.
Choices are...
A. (-2, 1), (-1, 2), (-1, 3)
B. (-2, 1), (-1, 1), (0, 1) (1, 1)
C. All of these
D. (-2, 1), (-2, 2), (-2, 3)
E. (-2, 1), (-2, 2), (-2, 3) and (-2, 1), (-1, 2), (-1, 3) only

Answer 1

Hi,
A) Not a function, -1 has the values 2 and 3.
B) Function. None of the values in the domain are repeated.
C) No.
D) Not a function. -2 has the vlaues 1, 2, and 3
E) Neither of these is a function since in the first one, -2 has three different values and in the second one, -1 has two different values.

Here's the definition we use to decide: Each "x" in the domain must have one and only one image in the range, y. But notice that more than one "x" in the domain can have the same value in the range.

FE