互易定理之 V(s) N Ia(s) Y,(s 互易定理之一告知 Y21(S)=Y12(S) L,(s) a(S)2(s) 或若 (s)=(s) S 则1(s) B 互易定理之二 l2( Va(s) 互易定理之二告知 S 221(S)=Z12(s) S N1()2() 则 B互易定理之一 21 ( ) ( ) ( ) I s Y s V s   = 12 ˆ ( ) ( ) ˆ ( ) I s Y s V s   = 互易定理之一告知 Y21(s)=Y12(s) 或若 ˆ V s V s ( ) ( )   = 则 ˆ I s I s ( ) ( )   = 互易定理之二 21 ( ) ( ) ( ) V s Z s I s   = 12 ˆ ( ) ( ) ˆ ( ) V s Z s I s   = 互易定理之二告知 Z21(s)=Z12(s) 或若 ˆ I s I s ( ) ( )   = 则 ˆ V s V s ( ) ( )   =   '   ' I s( ) V s( )   N +−   '   ' ˆ I s( )  ˆ V s( ) N    '   ' V s( )  I s( )  N +−   '   ' ˆ V s( )  ˆ I s( ) N  +−