Question

Which of the following relations represents a function?

a {(2, 3), (1, 3), (3, 3)}
c. {(1,3), (2, 3), (1,4)}
b. {(1, 3), (2, 3), (2,4)}
d. {(2, 2), (2, 3), (2, 1)}

Answer 1

A

Explanation:

A is the only one that has an x-value that has a unique y-value. C b and d have multiple x-values that have multiple y-values. For example, c has an x-value of 1 which has 2 outputs, which are 3 and 4.

Answer 2

D

Explanation:

Each function needs to have a unique output... i.e: plugging in a value for x, you get a unique value of y. D is the only one where that occurs :)