Approximately n-order linear dierential equations

We prove the generalized Hyers{Ulam stability of n-th order linear differential equation of the form y(n)+p1(x)y(n-1)+...+pn-1(x)y0+pn(x)y = f(x); with condition that there exists a non{zero solution of corresponding homogeneous equation. Our main results extend and improve the corresponding results obtained by many authors.