The object of this paper is to determine Hyers–Ulam–Rassias stability concerning the Jensen functional equation in intuitionistic fuzzy normed space (IFNS) by using the fixed point method. Further, we establish stability of the Cauchy functional equation in IFNS.

In the present paper a certain form of the Hyers–Ulam stability of monomial functional equations is studied. This kind of stability was investigated in the case of additive functions by Th. M. Rassias and Z. Gajda.

A boundary-value problem for a couple of scalar nonlinear differential equations with delay and several generalized proportional Caputo fractional derivatives is studied. Ulam-type stability the given investigated. Sufficient conditions existence an arbitrary parameter are obtained. In study stability, this was chosen to depend on solution corresponding inequality. We provide sufficient Ulam–Hy...

In this paper, we investigate the generalized Hyers-Ulam stability of a bi-reciiprocal functional equation in quasi-β-normed spaces. AMS Mathematics Subject Classification (2010): 39B82, 39B72

The generalized Hyers–Ulam–Rassias stability of generalized derivations on unital normed algebras into Banach bimodules is established. ∗2000 Mathematics Subject Classification. Primary 39B82; Secondary 46H25, 39B52, 47B47.

In this paper, we study Hyers–Ulam and generalized Hyers–Ulam–Rassias stability of a system hyperbolic partial differential equations using Gronwall’s lemma Perov’s theorem.

We will apply a fixed point method for proving the Hyers–Ulam stability of the functional equation f(x+ y) = f(x)f(y) f(x)+f(y) .

We apply the Luxemburg–Jung fixed point theorem in generalized metric spaces to study the Hyers–Ulam stability for two functional equations in a single variable.

We study the generalized Hyers-Ulam stability of the functional equation f[x1,x2,x3]= h(x1+x2+x3). 2000 Mathematics Subject Classification. 39B22, 39B82.