Question

Which of the sets of ordered pairs represents a function? (5 points)

A = {(2, −2), (5, −5), (−2, 2), (−5, 5)}
B = {(4, 2), (4, −2), (9, 3), (9, −3)}


Only A
Only B
Both A and B
Neither A nor B

Answer 1

The answer is A only

Explanation:

The relation is a function if every x in each order pair has only one image of y means:

In set A

x = 2 has only y = -2

x = 5 has only y = -5

x = -2 has only y = 2

x = -5 has only y = 5

That means x not repeated

∴ Set A is a function

In set B

x = 4 has y = 2 and y = -2

x = 9 has y = 3 and y = -3

∵ x has more than one image in y

∴ Set B not a function

Answer 2

Only A

Explanation:

By using the definition of a function:

A special relationship where each input has a single output.

In relation A for each value of x as input we have a single output y

For x = 2, y = -2,

x = 5, y = -5

x = -2, y = 2

x = -5, y = 5

Where as in B for each value of x we have two value of y

For x = 4 we have 2 and -2

For x = 9 we have 3 and -3

This condition violates the definition of a function