S2+3S+5 例：求F(S)-S3+6S2+11S+6 的反变换 S2+3S+5 K1,K2,K3 FS)S+1S+2S+3)s++s+2+s+3 K=(S+1)FS)= S2+3S+5 =1.5 (S+2)S+3)s--1 K2-(S+2)FS)=S2+3S+5 =-3 (S+1)S+3)川s=-2 K,=(S+3)FS=S2+3S+5 =2.5 (S+1)S+2)S=-3 F(S) 8篇+品+篇 S2+3S+5 ft)=f-1[F(S)]=1.5e-t-3e-2t+2.5e-3t (t≥0) (S+1)(S+2)(S+3) S 2+3S+5 F(S)= S+1 S+2 S+3 1.5 –3 2.5 = + + f(t)=£–1[F(S)]=1.5e–t–3e–2t+2.5e–3t (t t 0) (S+1)(S+2)(S+3) S 2+3S+5 F(S)= ֻ˖≲ Ⲵ৽ਈᦒ S 3+6S2+11S+6 S 2+3S+5 F(S)= S+1 S+2 S+3 K1 K2 K3 = + + K1=(S+1)F(S)=(S+2)(S+3) S 2+3S+5 S= –1 =1.5 K2=(S+2)F(S)=(S+1)(S+3) S 2+3S+5 S= –2 = –3 K3=(S+3)F(S)=(S+1)(S+2) S 2+3S+5 S= –3 = 2.5