Functional equations in matrix normed spaces (Q746362)

The authors use the well-known fixed point method to prove the Hyers-Ulam stability of the Cauchy functional equation \(f(x+y)=f(x)+f(y)\) and the quadratic functional equation \(f(x+y)+f(x-y)=2f(x)+2f(y)\) in the setting of matrix normed spaces.