On the stability of the quadratic functional equation on bounded domains



A result of Skof and Terracini will be generalized; More precisely, we will prove that if a functionf : [-t, t]nE satisfies the inequality (1) for some δ > 0 and for allx, y ∈ [-t, t]n withx + y, x - y ∈ [-t, t]n, then there exists a quadratic functionq: ℝnE such that ∥f(x) -q(x)∥ < (2912n2 + 1872n + 334)δ for anyx ∈ [-t, t] n .

Key words and phrases

Hyers-Ulam stability quadratic equation 


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Copyright information

© Mathematische Seminar 1999

Authors and Affiliations

  1. 1.Mathematics Section/Physics SectionCollege of Science & Technology, Hong-Ik UniversityChochiwonSouth Korea

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