Hyers-Ulam Stability of Lagrange’s Mean Value Points in Two Variables

Abstract

Using a theorem of Ulam and Hyers, we will prove the Hyers-Ulam stability of two-dimensional Lagrange’s mean value points ( η , ξ ) which satisfy the equation, f ( u , v ) − f ( p , q ) = ( u − p ) f x ( η , ξ ) + ( v − q ) f y ( η , ξ ) , where ( p , q ) and ( u , v ) are distinct points in the plane. Moreover, we introduce an efficient algorithm for applying our main result in practical use.