Question

Which relation does not represent a function? A) a vertical line B) y = 5 9 x - 3 C) a horizontal line D) {(1, 7), (3,7), (5, 7), (7,7)}

Answer 1

Answer:

A) a vertical line does not represent a function.

Step-by-step explanation:

For a relation to be a function for each value of $x$ there must be only one value of $y$. In other words a function is one in which each value in the domain set corresponds to only one value in the range set.

Let us check for this condition in the give choices:

A) a vertical line

A vertical line is given as $x=a$ which meas it is parallel to y-axis and has infinite number of $y$ values for a single $x$ value.

So, its  Not a function.  

B) $y=\frac{5}{9}x-3$

For the given equation, on plugging in some $x$ value will give a single $y$ value.

So, its a Function.

C) a horizontal line

A horizontal line is given as $y=a$ which meas it is parallel to x-axis and has infinite number of $x$ values giving a single $y$ value.

So, its a  Function .

D) {(1, 7), (3,7), (5, 7), (7,7)}

For the given set for different $x$ valuesthere is only one $y$ value.

So, its a  Function .