题目

求一下矩阵的逆矩阵
1 3 6
2 4 3
3 2 4

提问时间：2020-11-21

答案

(A,E) =
1 3 6 1 0 0
2 4 3 0 1 0
3 2 4 0 0 1
r2-2r1,r3-3r1 得
1 3 6 1 0 0
0 -2 -9 -2 1 0
0 -7 -14 -3 0 1
r3-4r2
1 3 6 1 0 0
0 -2 -9 -2 1 0
0 1 22 5 -4 1
r2+2r3
1 3 6 1 0 0
0 0 35 8 -7 2
0 1 22 5 -4 1
r2*(1/35),r2r3
1 3 6 1 0 0
0 1 22 5 -4 1
0 0 1 8/35 -7/35 2/35
r1-6r3,r2-22r3
1 3 0 -13/35 42/35 -12/35
0 1 0 -1/35 14/35 -9/35
0 0 1 8/35 -7/35 2/35
r1-3r2
1 0 0 -2/7 0 3/7
0 1 0 -1/35 2/5 -9/35
0 0 1 8/35 -7/35 2/35
逆矩阵就是后面那个3*3的.