Provide solution for RD Sharma maths class12 Chapter Functions exercise 2.1 question 16
Given:
Here given that is the set.
Here we have find all onto function from the given set.
Hint:
Since if f is onto then all element have a unique pre image.
Solution:
Taking the set
Total number of one-one function
As example since f is onto, all elements of have unique pre-image
Element | Number of possible pairs |
1 | 3 |
2 | 2 |
3 | 1 |
So as the diagram, we get
Elements | Number of possible pairs |
1 | n |
2 | n-1 |
3 | n-2 |
. | . |
. | . |
n-1 | . |
n | 2 |
1 |
So as the diagram, we get