Thursday, 10 January 2013

Function in Graphs

Example of function

   From this graph, we can tell that the vertical line will only touches one point of the graph and hence it is qualified as a function

 From this C-shaped graph, the vertical line will always touch 2 points of this graph and hence it is not qualified as a function because it has 2 possible output.


  1. Great! You have just used the vertical line test to determine if the graph is a function. Question: What does a horizontal line test do?