select all of the following graphs which are one-to-one functions.

Explanation:

Step1: Recall one-to-one test

A function is one-to-one if no horizontal line intersects its graph more than once (Horizontal Line Test).

Step2: Test first graph

Any horizontal line will cross the decreasing curve at most once. It passes the test.

Step3: Test second graph

Any horizontal line will cross the increasing curve at most once. It passes the test.

Step4: Test third graph

Any horizontal line will cross the straight line at most once. It passes the test.

Answer:

• The top graph (decreasing curve starting at (1,1))
• The middle graph (increasing curve starting left flat)
• The bottom graph (straight line with positive slope)