SUPERSTABILITY AND STABILITY OF (r; s; t)-J*-HOMOMORPHISMS: FIXED POINT AND DIRECT METHODS.

In this paper, we introduce the following useful functional equations: f(x+y) + f(x-2y) + f(y-x)= f(x) f (∑i=1p xi/p-1) + p∑fi=2p ∑j=1,j≠ixj- pxi/p-1) + f(∑i=2pxi-x1/p-1) = f(x1)and prove the superstability and the Hyers-Ulam stability of (r; s; t)-J*-homomorphisms, associated with those, by using the fixed point method and the direct method. [ABSTRACT FROM AUTHOR]