Guided Example #1 - Inverse Functions and One-to-One Functions

Which of the following functions is one-to-one?

a. y=3
b. h={(2,3),(1,2),(5,2),(3,17)}
c. y=|x|
d. g={(2,3),(1,2),(5,1),(3,17)}

 

The correct answer is D. To see why, view each of the steps below.

 

Step 1

The functions y=3 is a horizontal line and therefore it does not pass the horizontal line test. y=|x| is not one-to-one either for the same reason. The function h is not one-t0-one because of the ordered pairs (1,2),(5,2). The function g is one-to-one.

All Steps

The functions y=3 is a horizontal line and therefore it does not pass the horizontal line test. y=|x| is not one-to-one either for the same reason. The function h is not one-t0-one because of the ordered pairs (1,2),(5,2). The function g is one-to-one.