The Ulam stability of various equations (eg, differential, difference, integral, and functional)
concerns the following issue: how much does an approximate solution of an equation differ …

The problem of Ulam stability for equations can be stated in terms of how much the
mappings satisfying the equations approximately (in a sense) differ from the exact solutions …

Let V and W be linear spaces. A map f: V→ W is said to be 1. quadratic if f (x+ y)+ f (x− y)= 2f
(x)+ 2f (y), 2. quadratic of Jensen type if 2f (x+ y 2)+ 2f (x− y 2)= f (x)+ f (y) for all x, y∈ V. In …

In this paper, we first establish a stability result for a functional equation in single variable in
complete b-metric spaces. This result can be applied to prove the stability of various …

The present paper considers a fractional-order smoke epidemic model. We apply fuzzy
systems and probability theory to make the best decision on the stability of the smoking …

Using the Brzdȩk fixed point theorem, we establish the Hyers–Ulam stability of the following
generalized Drygas functional equation F ( x + σ ( y ) ) + F ( x + τ ( y ) ) = 2 F ( x ) + F ( σ ( y ) ) …

In this paper, we study the hyperstability problem for the well‐known σ‐Jensen's functional
equation f (xy)+ f (xσ (y))= 2f (x) for all x, y∈ S, where S is a semigroup and σ is an involution …

The main target of this book is to present a new concept of Ulam-type stability, ie, multi-
stability, through the classical, well-known special functions and to obtain the best …

Hyers–Ulam stability of the Drygas type functional equation | The Journal of Analysis Skip to
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Let V and W be vector spaces over rationals, n∈ N with n≥ 2. In this paper, we will reduce
the system of n cubic equations which define a multicubic mapping f: V n−→ W to obtain a …