Question #04245
1 Answer
The graph has to pass the vertical line test and the horizontal line test.
Explanation:
To pass the vertical line test, you should be able to draw a vertical line anywhere on the graph and no 2 points of the graph will cross the vertical line at the same time. If it passes this test, it is a function.
But for it to be one to one, it must pass the horizontal line test too. To pass the horizontal line test, you should be able to draw a horizontal line anywhere on the graph and no 2 points of the graph will cross the horizontal line at the same time.
If it passes both these tests it is a one to one function.
If a graph fails the vertical line test, it is not a function, so even if it passes the horizontal line test, it still can not be a one to one function.
