Question

Which of the following relations is a function?

Answer 1

Answer: D. {(0, - 4), (1, - 4), (2, 4), (3, 4), (4, - 4)}

Step-by-step explanation:

• A relation R is said to be a function if for each input value there exists only one unique output value.

In (x,y)  , x= Input value , y= output value.

A. {(-1, - 4), (-1,0), (- 1,5), (- 1, 7), (-1,9)}

Here, -1 has two output values -4 and 0.

So it is not a function.

B. (-2, - 4), (-1,7), (1, - 1), (1, 1), (3,9)}

Here, 1 has two output values -1 and 1.

So it is not a function.

C. {(-4,9), (- 3, 1), (- 2, 3), (- 2, 12), (0, 6) }

Here, -2 has two output values 3 and 12.

So it is not a function.

D. {(0, - 4), (1, - 4), (2, 4), (3, 4), (4, - 4)}

here, each input value has an unique output value.

Hence, D. option is correct.