Is 2y=x is a Function or not?

Question

Function or Not?

Answer 1

This is equivalent to

 

y = x/2

 

Now ask yourself, is there only one value of y for each value of x?  If so, it is a function.  If not, it is not a function.

Answer 2

y=(1/2)x

it is a function since it a line that is not vertical. 

Any x-value has only 1 y value