


Paper Title:
On the Ulam Stability for EulerLagrange Type Quadratic Functional Equations
Author(s):
Matina John Rassias and John Michael Rassias
Statistics and Modelling Science,
University of Strathclyde,
Livingstone Tower,
26 Richmond Str,
Glasgow, Uk, G1 1xh
Pedagogical Department, E. E., National and Capodistrian University of Athens,
Section of Mathematics and Informatics,
4, Agamemnonos Str, Aghia Paraskevi,
Athens 15342, Greece
Abstract:
In 1940 (and 1968) S. M. Ulam proposed the wellknown Ulam stability problem. In 1941 D.H. Hyers solved the HyersUlam problem for linear mappings. In 1951 D. G. Bourgin has been the second author treating the Ulam problem for additive mappings. In 1978 according to P.M. Gruber this kind of stability problems is of particular interest in probability theory and in the case of functional equations of different types. In 19822004 we established the HyersUlam stability for the Ulam problem for different mappings. In 19922000 J.M. Rassias investigated the Ulam stability for EulerLagrange mappings. In this article we solve the Ulam problem for EulerLagrange type quadratic functional equations. These stability results can be applied in mathematical statistics, stochastic analysis, algebra, geometry, as well as in psychology and sociology.
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