Question

工程数学 线性代数题目，求大神解答！在线等大神！

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Answer 1

9. P = A31+3A32-2A33+2A34 =
| 3 1 -1 2|
|-5 1 3 -4|
| 1 3 -2 2|
| 1 -5 3 -3|
P =
| 0 1 0 0|
|-8 1 4 -6|
|-8 3 1 -4|
|16 -5 -2 7|
P = (-1)*
|-8 4 -6|
|-8 1 -4|
|16 -2 7|
P = 8*
| 1 4 -6|
| 1 1 -4|
|-2 -2 7|
P = 8*
| 1 4 -6|
| 1 1 -4|
| 0 0 -1|
P = A31+3A32-2A33+2A34
= 8(-1)(1-4) = 24
8(1) 按第 2,3，......, n-1 行展开，得
D<n>= a^(n-2)(a^2-1)
(4) D =
| a 1 0 0|
|-1 b 1 0|
| 0 -1 c 1|
| 0 0 -1 d|
D =
| 0 1+ab a 0|
|-1 b 1 0|
| 0 -1 c 1|
| 0 0 -1 d|
D =
|1+ab a 0|
|-1 c 1|
| 0 -1 d|
D =
|1+ab a ad|
|-1 c 1+cd|
| 0 -1 0|
D =
|1+ab ad|
|-1 1+cd|
D = 1+ab+cd+ad+abcd