Let and let be a function from to State whether is one-one.

Solution:

We need to state: Whether is one-one
Given that:
Here the function is defined from
For a function to be one-one if the images of distinct elements of A under are distinct i.e. 1,2 and 3 must have a distinct image.
From we can see that 1,2 and 3 have distinct image.
Hence, is one-one
Ans) is one-one.