HH sY(S)-1+2sY(s)-3Y(S) s+1 解出Y(s) s2Y(s)-1+2s(s)-3Y(s)1 S+1 (s2+2s-3)Y(s) S+/1S+2 s+1 s+2 Y(S (S+1)s2+2s-3) 2士√4+12「1 s2+2s-3=0的解为s6 由 解出Y(s) 1 1 ( ) 1 2 ( ) 3 ( ) 2 + - + - = s s Y s sY s Y s    - = -  + + - = = + + - + = + + + = + + - = + - + - = 3 1 2 2 4 12 2 3 0 ( 1)( 2 3) 2 ( ) 1 2 1 1 1 ( 2 3) ( ) 1 1 ( ) 1 2 ( ) 3 ( ) 2 2 2 2 s s s s s s s Y s s s s s s Y s s s Y s sY s Y s 的解为