If f: A B be a function such that two different elements of A have two different images in B , then the function is called one-one function or injection or injective mapping : If f: A B be a function such that two different elements of A have two different images in B , then the function is called one-one function or injection or injective mapping
If f: A B be a function such that there exists at least two different elements of A which have the same images in B , then the function is said to be many-one function : If f: A B be a function such that there exists at least two different elements of A which have the same images in B , then the function is said to be many-one function
If f: A B be a function such that there exists at least one pre-image of every element of B in A , then the function is said to be an onto function or surjection : If f: A B be a function such that there exists at least one pre-image of every element of B in A , then the function is said to be an onto function or surjection
If f: A B be a function such that there exists at least one element of B which has no pre-image in A , then the function is said to be an into function : If f: A B be a function such that there exists at least one element of B which has no pre-image in A , then the function is said to be an into function
Slide 5 : One- one function
or Injection Many-one function Onto function
or Surjection Into function