Answer: Option C
Step-by-step explanation:
By definition, a relation is considered a function if and only if for each input value x there is only one associated output y value.
To verify if the graph of a relation is a function, trace on the graph vertical lines parallel to the y axis. If one of these vertical lines cuts the graph in 2 or more points, then the relationship is not a function
By definition, a function is considered a one-to-one function if and only if there is no equal output value and, for two different input values.
For example, the following ordered pairs do not correspond to a one-to-one function, because the output value y = 6 is associated with two input values x = 1 and x = 3
(1, 6) (3, 6)
To verify if the graph of a relation is a function, draw on the graph horizontal lines parallel to the x axis. If one of these horizontal lines cuts the graph in 2 or more points, then the relationship is not a one-to-one function.
When you draw vertical lines on the plot shown, you will see that they always intersect at a single point. Therefore the relationship is a function
When drawing horizontal lines on the displayed graph you will notice that they always intersect at a single point. Therefore the function is a one-to-one function
the answer is C
