(2)部分分式法 X(t)的拉氏变换Y(S,X(S) M(S N(S) ∑ S+s i=1 而L[4s1 S =Ac,而zAc1=_4z Si oo X(Z)=∑ A12 7=2-e-S( ) [ ] , [ ] ( ) ( ) ( ) ( ), ( ) 1 1 1 0 0    = − − − − + −  = + −  = − = = = = i S T i S T S t S t i S S i A i S S A i i i i i i i i Z e A Z X Z Z e A Z L A e Z A e N S M S X t X S X S 而 而 的拉氏变换 (2) 部分分式法