and
Djki, k = 1, 2, 3, . . . , N, are constant factors different from zero.
Proof:
From linear algebra results, that the determinant of matrix (I - βP ) always exist,
it is bigger than zero and it is a polynomial of N - degree. Each polynomial of N -
degree has exactly N different real roots. Hence we can show det (I - βP ) in form
(16). Let prove (15) and write this formula in the following form:
[Dji (β )] = [⅞] + jd⅛l ...JDNL
(17)
det (I — βP) (1 — α1β) (1 — α2β) (1 — αNβ)
This formula shows decomposition of the left side of dependence (17) into sum
of N partial fractions. Such a decomposition is always possible. If we want to cal-
culate values of factors Djki, k = 1, 2, 3, . . . , N, we should solve (N × N) systems
of equations:
Dji (β)
det (I — βP)
D1 D2. Dn ___
(18)
--j— +--j— + +--j-— ij = 1 N
1 — αι β +1 — α2β + +1 — αN β ,j ,
it means
Dji (β) = Dji (1 — α2β) ... (1 — αNβ) + Dji (1 — α1β) (1 — α3β) . . .
det (I — βP) det (I — βP)
... (1 — αNβ) + ... + DjN (1 — αιβ) (1 — α2β)... (1 — αN-ιβ)
det (I — βP)
After rejection of denominators of both sides we compare factors which stand in
front of the same powers β, β0, β1 , . . . , βN-1 of the left and right side of nume-
rators.
So each element of matrix
[Dji (β)] = Γ Dji (β)
i,j = 1,N
det (I — βP) det (I — βP)