By using the z-transforms

Consider the difference equation: x(k + 2) - 1.3679x(k + 1) + 0.3679x(k) = 0.3679u (k + 1) + 0.2642u(k) where x(k) = 0 for k lessthanorequalto 0. The input u(k) is given by u(k) = 0, k