Q.
There are three relations R1,R2 and R3 such that R1={(2,1),(3,1)(4,2)} R2={(2,2),(2,4),(3,3),(4,4)} and R3={(1,2),(2,3),(3,4),(4,5),(5,6),(6,7)}
Then,
Since 2,3,4 are the elements of domain of R1 having their unique images, this relation R1 is a function.
Since, the same first element 2 corresponds to two different images 2 and 4 , this relation R2 is not a function.
Since, every element has one and only one image, this relation R3 is a function.