f(x + y)f(x - y) = (f(x)f(y))^2
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October 11, 2010
functioninductionquadraticsalgebradomainalgebra unsolved
Problem Statement
Determine all continuous functions such that
f(x + y)f(x - y) = (f(x)f(y))^2, \forall(x, y) \in\mathbb{R}^2.
Source: