Question

Which of the following relations is a function?

A.{(2,6),(3,9),(4,2),(3,6)}

B.{(2,8),(3,6),(2,4),(0,2)}

C.{(3,-2),(4,7),(-2,5),(-4,5)}

D.{(4,7),(-2,5),(1,3),(-2,1)}

Answer 1

A 2,6,3,94,2,3,6 its the most reasonable.

Answer 2

For a relation to be a function, it can only have 1 of each number as an X value.
If there are 2 or more identical X values it cannot be a function.
The X value is the first value inside the parenthesis. (X,Y)


A has 2 3's as an X value so cannot be a function.
B has 2 2's as an X value so cannot be a function.
C has no multiple X values so is a function.
D has 2 -2's as an X value so cannot be a function.

The answer is C.