SOLUTION: how can you tell relations is a function on a graph?

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Question 358884: how can you tell relations is a function on a graph?
Answer by neatmath(302) About Me  (Show Source):
You can put this solution on YOUR website!
The easiest way to tell if the graph of a relation is a function is to use the vertical line test!

If you draw a vertical line through any (and all) points on the graph, and the vertical line touches 2 or more points on the graph, then it is NOT a function!

Remember functions have a 1 to 1 relationship.

For each x value, there is 1 and only 1 y value.

So if any x value has 2 or more y values, it can NOT be a function.

The vertical line test will show this to you graphically.

If you draw a vertical line through any (and all) points on the graph, and the vertical line touches only 1 point on the graph, then it is a function!

I hope this helps!