Ulam stability problem for generalized A-quadratic mappings

It is the purpose of this paper to investigate the stability problem of Ulam for an approximate mapping for the following generalized quadratic functional equation: ∑i=1nQ(∑j≠ixj−(n−1)xi)+nQ(∑i=1nxi)=n2∑i=1nQ(xi) for all xi(i=1,…,n), where n>1.