Can you look at this crappily drawn graph...?

Question

...and tell me if y is or is not a function of x?

http://i6.tinypic.com/8bhphjr.jpg

Answer 1

yes!

you can prove it by drawing two vertical lines
if the it is a function, then it won't cross the vertical lines twice

Answer 2

Hi,
Actually, it probably is. The test is to imagine a vertical line moving from left to right on the graph and if the line cuts the graph in more than one place, then the graph is not a function.

Now, with your graph there appears to be a vertical section and a horizontal section, either of which would disqualify it. But my guess is that that is a result of some lack of diligence :-) in reproducing the graph rather than a true graph of the function.

FE

Answer 3

no, it is not a function , use the vertical line test and you can see you have a vertical line on your graph which cuts through a lot of points at the same time