COMPSCI 70 Chapter Notes - Chapter 7: Modular Multiplicative Inverse, Public-Key Cryptography, Inverse Function
31 Jan 2018
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9:30 pm function - a mapping from the domain (a set of inputs a) to a set of outputs (range) in b (codomain) For input , must be in the set b. A function is a bijection if and only if . However, the actual codomain may be larger than the size of the range. Every y value has at least 1 x value. All y values have 1+ x values bijection - a function that is one-to-one (has a unique inverse) and onto (domain and co-domain/range have the same size) If a y value gets mapped to, then it has 1 x value. All x"s map to a unique y in the codomain. All y"s have at most 1 x (all y"s have 0-1 x values) How to prove a function is one-to-one is one-to-one (injective) (uniqueness) If there exists an injective function , then see cardinality notes.
