EDGE Math 8

1.	Which of the following statements is false?

A function is a correspondence between two sets, say X and Y, that assigns to each element x of X exactly one element y of Y.

A function is a relation where no two distinct ordered pairs in it have the same second coordinate.

An example of a function is the set of ordered pairs

{(2, 5), (3, 1), (4, 4)} .

All functions are relations, but not all relations are functions.

Answer: A function is a relation where no two distinct ordered pairs in it have the same second coordinate.

2.	Which of the following relations is not a function?

{(1, 3), (1, 4), (2, 5)}

{(1, 3), (2, 4), (3, 5)}

{(1, 3), (2, 3), (3, 3)}

None of the choices

Answer: ${(1, 3), (1, 4), (2, 5)}$

3.	What do you call the set of all first coordinates of the ordered pairs?

domain

range

y-coordinates

None of the choices

Answer: domain

4.	Which of the following equations is not a function?

y = x

y = x^{2}

y^{2} = x

None of the choices

Answer: $y^{2} = x$