For one to one function each element in the domain is mapped on to an one and only one element in the co-domain.
The could be some elements in the co-domain that are not being used.
For a function to be one to one, then for
if and only if
For an onto function all the elements in the co-domain must be used up.
In order words, the
The condition is
Meaning each
The could be some elements in the co-domain that are not being used.
For a function to be one to one, then for
if and only if
For an onto function all the elements in the co-domain must be used up.
In order words, the
The condition is
Meaning each