Functional Equations and Inequalities

Preface. On the Stability of a Functional Equation for Generalized Trigonometric Functions R. Badora. Some Notes on Two-Scale Difference Equations L. Berg, G. Plonka. Some Demand Functions in a Duopoly Market with Advertising E. Castillo, et al. Solutions of a Functional Inequality in a Special Class of Functions M. Czerni. On Dependence of Lipschitzian Solutions of Nonlinear Functional Inequality on an Arbitrary Function M. Czerni. The Problem of Expressibility in Some Extensions of Free Groups V. Faiziev. On a Pythagorean Functional Equation Involving Certain Number Fields J.L. Garcia-Roig, J. Salillas. On a Conditional Cauchy Functional Equation Involving Cubes J.L. Garcia-Roig, E. Martin-Gutierrez. Hyers-Ulam Stability of Hosszu's Equation P. Gavruta. The Functional Equation of the Square Root Spiral K.J. Heuvers, et al. On the Superstability of the Functional Equation f(xy)=f(x)y S.-M. Jung. Replicativity and Function Spaces H.-H. Kairies. Normal Distributions and the Functional Equation f(x+y) g(x-y) = f(x) f(y) g(x) g(-y) P.L. Kannappan. On the Polynomial-Like Iterative Functional Equation J. Matkowski, W. Zhang. Distribution of Zeros and Inequalities for Zeros of Algebraic Polynomials G.V. Milovanovic, T.M. Rassias. A Functional Definition of Trigonometric Functions N.N. Neamtu. A Qualitative Study of Lobachevksy's Complex Functional Equation N.N. Neamtu. Smooth Solutions of an Iterative Functional Equation J.-G. Si, et al. Set-Valued Quasiconvex Functions and their Constant Selections W. Smajdor. Entire Solution of the Hille-type Functional Equation A. Smajdor, W. Smajdor. Ulam's Problem, Hyer's Solution - and to Where they Led L. Szekelyhidi. ASeparation Lemma for the Construction of Finite Sums Decompositions W. Tutschke. Aleksandrov Problem and Mappings which Preserve Distances S. Xiang. On Some Subclasses of Harmonic Functions S. Yalcin, et al. Index.