a ain a ain D C n D2=Cil n an1 ann nn 则由行列式的定义, D=∑( T(PiP2"Pn) a (b1n,+Ci,) 11 ip P ∑(-1)mpPa1n…bn…a +>(1) P1 P2 "Pn/alpr" Cip: " npn =D1+D 上页下 圆回1 1 1 1 1 1 1 1 1 2 1 1 , , n n i in i in n nn n nn a a a a D D b b c c a a a a = = " " " " " " " " " " " " " " " " " " 则由行列式的定义, 1 2 1 1 2 1 1 2 1 ( ) 1 ( ) 1 ( ) 1 1 2 ( 1) ( ) ( 1) ( 1) . n i i n n i n n i n p p p p ip ip np p p p p ip np p p p p ip np D a b c a a b a a c a D D τ τ τ = − + = − + − = + ∑ ∑ ∑ " " " " " " " "