Additive function
Different definitions exist depending on the specific field of application. Traditionally, an additive function is a function that preserves the addition operation:f(x+y) = f(x)+f(y) for any two elements x and y in the domain.In
number theory, an additive function is an
arithmetic function f(n) of the positive
integer n such that whenever a and b are
coprime, the function of the product is the sum of the functions:f(ab) = f(a) + f(b).The remainder of this article discusses number theoretic additive functions, using the second definition. For a specific case of the first definition see
additive polynomial. Note also that any
homomorphism f between
Abelian groups is "additive" by the first definition.
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Fonction additive
Additivität
Funzione additiva
Additiv funktion