3.积分性质若<[()=F(s) 贝 f(tdt=F(s) (28) 证设h()=f()dt,则有 h'(t)=f(t),且h(0)=0 由上述微分性质,有 [h(t)]=s[h(t)]-h(0)=s[h(t)], f(O)dr|=1[()2=-F()10 3. 积分性质 若L [f(t)]=F(s)   ( ) 1 ( ) 1 ( )d [ ( )] [ ( )] (0) [ ( )], , ( ) ( ), (0) 0 ( ) ( )d , ( ) (2.8) 1 ( )d 0 0 0 F s s f t s f t t h t s h t h s h t h t f t h h t f t t F s s f t t t t t = =      = - =  = = = =        L L L L L L 即 由上述微分性质 有 且 证 设 则有 则