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. Martín-Gutiérrez. Hyers-Ulam Stability of Hosszú'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. NormalDistributions 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. Székelyhidi. 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. Yalçin, et al. Index.