Functions? Mathhhh problem. Please help:(?

Question

Which of the following is a function?

a. {(-4,1), (1,8), (-4, -2)}

b. {(-4,1), (1,-8), (-2, -2)}

c. {(-4,1), (1,-8), (1, -2)}

d. none of these

Answer 1

In a function, for every value of x there is exactly one y value. for example, if, for x= 3, y=4, that is the ONLY value y can equal at x=3.

In a, the x value -4 has y values 1 AND -2. That means it is not a function.

In b, all the given x values have only one y value.

In c, 1 has two y values- -8 and -2

Therefore, the answer is (b)

Answer 2

B