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Function

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Types of Function

1. Injective Function(one to one)
The function is which distinct domain is associated with distinct elements of codomain is called injective function. Example; 



2. Surjective Function(onto)
 The function is which every codomain is associated with at least one domain is called surjective function. Example; 

3. Bijective Function(one to one onto)
→ The function which is both injective and surjective is called bijective function. Example; 


Properties of Composite of Function
Let f : A → B and g: B → C be the two functions, then function defined as A→ C is called composite function from A to C. The properties of such function are as follows:
↪ If f : A→B, : B→C and h: C→D are given functions, then: ho(gof) =(hog)of
↪ If f : A→B, : B→C are given functions, the gof  is onto or one-one according as each of f  and g is onto or one-one.