Question

Please help me:(

1. Give an example of relation which represents a function and explain how
it became a function.
2. Give (3) examples of graph and diagram mapping that represent a
function.​

Answer 1

1.For example, y = x + 3 and y = x2 – 1 are functions because every x-value produces a different y-value. A relation is any set of ordered-pair numbers

Answer 2

Which of the following relations are functions? Give reasons.  

If it is a function determine its domain and range

(i) {(2,1),(5,1),(8,1),(11,1),(14,1),(17,1)}

(ii) {(2,1),(4,2),(6,3),(8,4),(10,5),(12,6),(14,7)}

(iii) {(1,3),(1,5),(2,5)}

Answer

(i) {(2,1),(5,1),(8,1),(11,1),(14,1),(17,1)}

It is a function as every input has a single output.

So, 2,5,8,11,14 and 17 are the elements of the domain of the given relation.  

Here domain ={2,5,8,11,14,17} and range ={1}

(ii) {(2,1),(4,2),(6,3),(8,4),(10,5)(12,6),(14,7)}

It is a function as every input has a single output.

So, 2,4,6,8,10,12 and 14 are the elements of the domain of the given

relation.  

Here domain ={2,4,6,8,10,12,14} and range ={1,2,3,4,5,6,7}

(iii) {(1,3),(1,5),(2,5)}

Since the element  1 corresponds to two different images i.e., 3 and 5 . So, this relation is not a function.