Question

What is the difference between a relation and function? Classify each of the following as a function, or not a function. State the domain and range

{(1,7),(1,14),(1,21)}

The relation is/isn't a function
Domain _ _ _
Range _ _ _
Leave Unused Fields Blank

Answer 1

A relation is a subset of cartesian product of two non empty sets whereas A function is a type of relation in which every element of first set has one and only image in the second set.

In a relation an element of the first set can have many images in the second set whereas in a function the first element can have only one image in the second set.

The given relation is not a function as the element 1 is related to 3 different elements in the second set.

Domain={1}

Range={7,14,21}