The idea of pairing each member of the domain with each member of the range referred to as mapping.

Examples of Mapping

The figure shows a mapping of the elements of the domain to the elements of the range. Each element in the domain is increased by 1 to get the corresponding element in the range.

Solved Example on Mapping

Use the mapping diagram for the relation and determine whether {(3, - 1), (6, - 1),(3, - 2),(6, - 2)} is a function or not.

Choices:

A. Yes

B. No

Correct Answer: B

Solution:

Step 1: Draw the mapping diagram for the given relation.

Step 2: A relation is a function if each element in the domain is paired with one and only one element in the range.

Step 3: From the mapping diagram, it can be observed that the given relation is not a function as ‘3’ in the domain is paired with two elements - 1 and - 2 in the range and ‘6’ is paired with - 1 and - 2.