Answer:
Two
Explanation:
We are given that two sets and each set have two elements.
We have to find how many one- one function are formed from a set of two elements to a set with two elements.
Let A={a,b}
B={1,2}
One-to-One function:If a function is one-to-one then different elements of set A is mapped with different elements of set B.Two elements of set A have not same image.
If an element 'a' of set A is mapped with an element '1' of set B.
Then , element b of set A is mapped with element '2' of set B.
If an element 'a' of set A is mapped with element '2' of set B.
Then, only one choice for element b and it mapped with element '1' of set B.
Therefore, there are two possible cases and two one-to-one function are formed from a set of two elements to a set of two elements.
Hence,two one-to- one functions are formed from a set with two elements to a set with two elements