國營聯招 儀電控制系統95 年第 38 題單選題下列何者為因果系統(Causal system):Ay(t) = u(t-1)正確答案By(t) = u(-t+1)Cy(t) = u(t+1)Dy(t) = u(t) + u(t+2)Ey(t) = u(t²) 答案與詳解