Question

A function is given by a table of values, a graph, a formula, or a verbal description. Determine whether it is one-to-one.

Answer 1

Step 1 :

Horizontal line test :

A function is one-to-one if and only if no horizontal line intersects its graph more than once.

Step 2 :

Draw a horizontal line.

Observe the graph :

The horizontal line touches the graph at two points.

The function is not one-to-one, because it violates the horizontal line test.

Solution :

The function is not one-to-one.