What is an Inverse Function?

What is an Inverse Function?



If we have a function f : A ↦ B, there may exist an Inverse Function:

f^-1 : B ↦ A

which is defined by the rule f^-1 (b) = a where b = f(a). This definition only works if every b ∈ B is an image of some point under f (that is, the range equals the target) and if there is only one such point (that is, there is only one a for which f(a) = b)

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