On the stability problem for a mixed type of quartic and quadratic functional equation

Let E1 and E2 be real linear spaces. In this paper, we determine the general solution for a mixed type functional equation of a quartic and a quadratic mapping f : E1→E2, n−1 x2,...,xn f (x1)+ 2n−1(n− 2) n i=1 f (xi ) = 2n−2 1 i2. In addition we solve the generalized Hyers–Ulam–Rassias stability problem for the functional equation. © 2005 Elsevier Inc. All rights reserved