f(A)=f(\lambda)I + f'(\lambda)N+f''(\lambda)N^2...+f^{(8)}(\lambda)N^8={uvjet} =f(\lambda)I+ f^{(4)}(\lambda)N^4+...+f^{(8)}(\lambda)N^8 = f(\lambda)I+N^4(f^{(4)}(\lambda)+ostatak)