218 5. Further Determinant Theory
Once again the symbol←→ denotes that the columns are arranged in
reverse order.
Illustrations
B 2 (x)=
[
1
1 x
]
,
B 3 (x)=
1
12 x
13 x 4 x
2
,
B 4 (x)=
1
13 x
15 x 9 x
2
16 x 19 x
2
27 x
3
,
B 5 (x)=
1
14 x
17 x 16 x
2
19 x 37 x
2
64 x
3
110 x 55 x
2
175 x
3
256 x
4
.
Sincebijis a function ofn,Bnis not a submatrix ofBn+1. Finally, define
a block matrixN 2 nof order 2nas follows:
N 2 n=
[
O
Sn(x)
Bn(x) An
]
, (5.6.23)
whereAn=[αm]n, as before.
Illustrations
N 4 =
1
1 x
1 α 0 α 1
1 xα 1 α 2
,
N 6 =
1
13 x
1 xx
2
1 α 0 α 1 α 2
12 xα 1 α 2 α 3
13 x 4 x
2
α 2 α 3 α 4
N 2 nis symmetric only whenn=2.
A subset ofN 4 is: