Injective Surjective

Injective Surjective

Injective Surjective

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https://goo.gl/ZQy7rZ

https://goo.gl/hs28V8

One-one function (Injection)

A function f : A ⟶ B is said to be a one-one function or an injection, if different elements of A have different images in B. Thus, f : A ⟶ B is one-one.

a ≠ b ⇒ f(a) ≠ f(b) for all a, b ∈ A

⟺ f(a) = f(b) ⇒ a = b for all a, b ∈ A.

e.g. Let f : A ⟶ B and g : X ⟶ Y be two functions represented by the following diagrams.

injective surjective

injective surjective bijective

surjective injective

injective or surjective

injective vs surjective

surjective injective bijective

injective surjective and bijective

surjective bijective injective