§2-2传递函数 3.拉氏变换定理: Lf1(t)±f2(t)]=F1(s)±F2(s) 4f()=AF(s) 工f(t-)=eF(s) L=SF( 条件:f(0)=0.,即初始条件为0 f( ]=snF(s)条件:f0)=f(0=f"(0)=.f(m(0)=0 dt LI f(O)dr =F(s) 返回本节3. 拉氏变换定理： [ ( ) ( )] ( ) ( ) 1 2 1 2 L f t  f t = F s  F s L[Af (t)] = AF(s) L[ f (t )] e F(s) s  − − = ] ( ) ( ) [ sF s dt df t L = ] ( ) ( ) [ s F s dt d f t L n n n = s F s L f t dt ( ) [ ( ) ] = 条件：f(0)=0,即初始条件为0 条件：f(0)=f '(0)=f ''(0)=… f (n-1)(0)=0 返回本节 §2-2 传递函数