Algebra two help please!?

Question

Explain why a vertical line, rather than a horizontal line, is used to determine if a graph represents a function.

Thanks.

Answer 1

For y to be a function of x the property must hold true that for every x in the domain there cannot be two different y values.

The x values are on the horizontal line, when one draws a vertical line that line represents a particular x value if it crosses the graph in two places we know there aretwo different y values. Thus we do not have y as a function of x.

The reason we do not use a horizontal line is that would be a test to see if x was a function of y. It would test if for any y there was no more than one x.

Answer 2

because a vertical line or asymptote, determinates if you graph cuts more than one time this line...

Remember the definition of a function... For every value of "x" you can only have one image of "y"

And it is also a function if you have 2 values por "y" but only on "x"