二、微分性质 设￡f()=F(S) -SF(S)-0-) Lf'(】=Df'()et f(D)e"(-s)e"f(dr =sF(S)-f(0.) ic =Cduc dt 设[u]=Ue(s) i]=tc业]=c[sU.(s)-4,0.)] dt£ [ ]=SF(S)–f(0-) df(t) dt Ҽǃᗞ࠶ᙗ䍘 䇮 £ [f (t)]=F (S) C C du i =C dt uC C + - iC 䇮 s £ £ £ C C C C C C- [u ]= U (s) du [i ]= [C ]= C[ U (s)- u (0 )] dt - - - - 0 - - 0 0 - £[ ( )] ( ) ( ) - (- ) ( ) ( )- (0 ) f f f c c ³ ³ st st st f t f t e dt f t e s e f t dt sF s f