Horizontal Line Test

Author:
Carlos
A 1 to 1 function is where every x is mapped to a unique value of y, the mathematical term is injective An onto function is where every y is mapped from at least one x value, mathematical term is surjective. On the following graph, adjust the values of to move the line and find points of intersection between the line and the function . 1) Is this function 1-1? Explain your answer. 2) Are there any intervals for which is 1-1? 3) Is this function onto? Explain why.

Graph of f(x)

What about the function below: 1) Is 1-1? 2) Are there any intervals for which is 1-1? 3) Is this function onto? Explain why.

Graph of g(x)

What features should a graph have in order to represent a 1-1 function? What about an onto function? Test your conjectures by entering a function in the graph below and applying the appropriate tests.