
In this paper, we will introduce a new functional equation f (x 1, y 1) f (x 2, y 2) = f (x 1 x 2+ y 1 y 2, x 1 y 2 − y 1 x 2), which is strongly related to a well known elementary formula of number theory, and investigate the solutions of the equation. Moreover, we will also study the Hyers—Ulam—Rassias stability of that equation.
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| influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Average | |
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