求下列信号F()的拉氏反变换 2s+1K K 1.令F(s) s(S+1)ss+1 2×0+ K1=F(s)S0=-0+1 K2=F(s)(+1 则F(s)=-+>(1+e)E(t) sS+I三、 求下列信号F (s) 的拉氏反变换 ( 1) 1 2 1 1. ( ) 1 2 + = + + + = s K s K s s s 令F s ( ) ( 1) 1 1 0 1 2 0 1 ( ) 2 1 1 0 =  + = = +  + =  = =− = s s K F s s K F s s 则 e t） s s F s t (1 ) ( 1 1 1 ( )  −  + + = +