is x=-2 a function

Question

I am doing Representing Functions and im not sure how to find out if x=-2 is a function or if it is not a function

Answer 1

x = -2 is not a function. A function requires an input and an output. Examples:

 

y = x

f(x) = x²

 

 

Answer 2

Hi Jasmine;

The principle of a function is that each coordinate of the x axis is represented once.

For example...

x=1, corresponds to y=2

x=2, corresponds to y=4

x=3, corresponds to y=2

 

This equation is considered a function because each x-coordinate is represented once.  The fact that y=2 is represented twice is a non-issue.

 

x=-2, y=1

x=-2, y=2

x=-2, y=3

 

Do you see what is happening?  The line is vertical.  The x-coordinate -2 is represented throughout.  This is NOT a function.