Answer:
B. This is the graph of a function, but it is not one-to-one
Explanation:
A function is a type of graph that has a specific relationship between the x and y values.
Vocabulary
First, let's define the words that were used in the answer choices.
- Function - A function is a type of relationship where the x-values do not repeat. This means that each x-value has only one specific y-value.
- One-To-One - A one-to-one function still has no repeating x-values; however, y-values also do not repeat. This means that each y-value has only one x-value and vice versa.
Finding a Function
There are different ways to find if a relationship is a function, but with a graph, the easiest way is the vertical line test. The vertical line test is when you draw vertical lines over your graph. If you are able to draw a vertical line everywhere without that line crossing the graph more than once, then the graph is a function.
In this graph, there is no spot in which a vertical line would intersect with the graph more than once. Since it passed the vertical line test, this must mean that x-values never repeat. Thus, this is a function.
Finding a One-To-One Function
Now that we know this is a function, we need to find if this is a one-to-one function. Once again, this can be done multiple ways, but one way is the horizontal line test. This test is similar to the method above; however, horizontal lines are used. In this test, you draw horizontal lines are drawn on the graph. If you can draw a horizontal line at every value without the line intersecting more than once, then it is a one-to-one function.
On this graph, if you were to draw a horizontal line at any of the y-values between 0 and 6, then the line would intersect multiple times. This means that y-values do repeat. Thus, this is not a one-to-one function.