Question

Witch is not a function {(7,8),(−4,4),(3,8),(−7,−1)} \{(-5, -3), (-1, -8), (-7, 0), (-5, -9)\}{(−5,−3),(−1,−8),(−7,0),(−5,−9)} \{(8, 4), (6, -1), (-4, 5), (9, 4)\}{(8,4),(6,−1),(−4,5),(9,4)} \{(8, -3), (4, 0), (-4, 9), (3, 2)\}{(8,−3),(4,0),(−4,9),(3,2)}

Answer 1

Given:

The relations are:

{(7,8),(−4,4),(3,8),(−7,−1)}

{(-5, -3), (-1, -8), (-7, 0), (-5, -9)}

{(8,4),(6,−1),(−4,5),(9,4)}

{(8,−3),(4,0),(−4,9),(3,2)}

To find:

The relation that is not a function.

Solution:

A relation is a function if there exist unique y-value for each x-value and a relation is not a function if there exist more than one y-values for any x-value.

In option B, the given relation is:

{(-5, -3), (-1, -8), (-7, 0), (-5, -9)}

Here, $y=-3$ and $y=-9$ for $x=-5$. There exist more than one y-values for $x=-5$. So, this relation is not a function.

In other three relations, all x-values are different, so there exist unique y-value for each x-value. It means the relations in options A, C and D are functions.

Therefore, the correct option is B.