2频域导数性质 设:Lf()=F(S) 则:L-f( dF(S) 证:「f(t)e"dt=「f()(-t)eat =|-4() 推广:Lr"f()]=(-1) d F(S)2.频域导数性质 dS dF S L tf t ( ) 则： [− ( )] =   − 0− f (t)e dt ds 证：d st   − − = − 0 f (t)( t)e dt s t = L[−tf (t)] 设：L[ f (t)] = F(S) n n n n dS d F S L t f t ( ) 推广： [ ( )] = (−1)