Question

Which relation is a function?

A. {(1,2), (1,5), (1,-1), (1,4)}
B. {(8,-1), (2,-1), (3,8), (2,5}
C. {(-3,4), (-2,5), (0,9), (0,12)}
D. {(7,12), (1,-5), (3,-10), (2,-5)}

Answer 1

Answer: OPTION D

Explanation:

By definition, If in a relation the each input value (value of x) has one and only one output value (value of y), then the relation is called "Function".

The option A is not a function because input value (x=1) has more than one input value.

The option B is not a function because input value (x=2) has more than one input value.

The option C is not a function because input value (x=0) has more than one input value.

The option D is a function because each input value (value of x) has one and only one output value.

Answer 2

Choice D is the function.

Explanation:

We have given different sets of ordered pairs.

We have to find which relation is a function.

A function is a rule that assigns each input a exactly one output.

So, from definition of function the first three relation are not function.

Because a single input contain more than one output.

{(7,12), (1,-5), (3,-10), (2,-5)} this represents a function each input has only one output.

Choice D is correct.