Question

【急求】初等变换求逆矩阵123221343r3-r1-r2,我们教材都没有.

Answer 1

解: (A,E) =

1 2 3 1 0 0

2 2 1 0 1 0

3 4 3 0 0 1

r3-r1-r2,r2-2r1

1 2 3 1 0 0

0 -2 -5 -2 1 0

0 0 -1 -1 -1 1

r3*(-1),r1-3r3,r2+5r3

1 2 0 -2 -3 3

0 -2 0 3 6 -5

0 0 1 1 1 -1

r1+r2,r2*(-1/2)

1 0 0 1 3 -2

0 1 0 -3/2 -3 5/2

0 0 1 1 1 -1

所以 A^-1 =

1 3 -2

-3/2 -3 5/2

1 1 -1