线性代数!化成三角行列式!
来源:学生作业帮 编辑:搜搜考试网作业帮 分类:数学作业 时间:2024/08/06 07:06:51
线性代数!化成三角行列式!
2+r1/a、c3+c4/d
D=|a 1 0 0|
0 b+1/a 1 0
0 -1 c+1/d 1
0 0 0 d
r3+r2*[a/(ab+1)] 【成《《上三角》】
=|a 1 0 0|
0 b+1/a 1 0
0 0 c+1/d+a/(ab+1) 1
0 0 0 d
=a(b+1/a)[c+1/d+a/(ab+1)]d
=(ab+1)[cd+1+ad/(ab+1)]
=(ab+1)cd+(ab+1)+ad
=abcd+cd+ab+1+ad
=abcd+ab+cd+ad+1 【其实还不如按行(列)展开来得简单得多!】
D=|a 1 0 0|
0 b+1/a 1 0
0 -1 c+1/d 1
0 0 0 d
r3+r2*[a/(ab+1)] 【成《《上三角》】
=|a 1 0 0|
0 b+1/a 1 0
0 0 c+1/d+a/(ab+1) 1
0 0 0 d
=a(b+1/a)[c+1/d+a/(ab+1)]d
=(ab+1)[cd+1+ad/(ab+1)]
=(ab+1)cd+(ab+1)+ad
=abcd+cd+ab+1+ad
=abcd+ab+cd+ad+1 【其实还不如按行(列)展开来得简单得多!】