积分性质 设:Lf()=F(S) 则:LDf()=F(S) 证:fO=mmf()m LIf(=LIa Jo. f(t)drI F(S)=SLIS f(dr]-5o' f(dreo LI f(t)dt =F(S)三、积分性质 ( ) 1 [ ( ) ] 0 F S S L f t dt t  = − 则： [ ( )] [ ( ) ] 0 − = t f t dt dt d L f t L F(S) − − − =  −  =0 0 0 [ ( ) ] ( ) t t t sL f t dt f t dt =  − t f t dt dt d f t 0 证 ： ( ) ( ) 设 ：L[ f (t)] = F(S) ( ) 1 [ ( ) ] 0 F S S L f t dt t  = −