# Ch-3.2-exam-4-Revise-김강섭

## 1915 days ago by matrix

A=matrix(QQ, 3, 3, [1, 0, 0, 1, 3, 5, 8, 1, 2]) I=identity_matrix(3) Aug=A.augment(I).echelon_form() # augmented matrix [A : I] echelon_form show(Aug) B=matrix(QQ, 3, 3, [0, 1, 2, 8, 0, 7, 9, 0, 8]) Aug=B.augment(I).echelon_form() show(Aug) AB=A*B Aug=AB.augment(I).echelon_form() show(Aug)
 \newcommand{\Bold}[1]{\mathbf{#1}}\left(\begin{array}{rrrrrr} 1 & 0 & 0 & 1 & 0 & 0 \\ 0 & 1 & 0 & 38 & 2 & -5 \\ 0 & 0 & 1 & -23 & -1 & 3 \end{array}\right) \newcommand{\Bold}[1]{\mathbf{#1}}\left(\begin{array}{rrrrrr} 1 & 0 & 0 & 0 & 8 & -7 \\ 0 & 1 & 0 & 1 & 18 & -16 \\ 0 & 0 & 1 & 0 & -9 & 8 \end{array}\right) \newcommand{\Bold}[1]{\mathbf{#1}}\left(\begin{array}{rrrrrr} 1 & 0 & 0 & 465 & 23 & -61 \\ 0 & 1 & 0 & 1053 & 52 & -138 \\ 0 & 0 & 1 & -526 & -26 & 69 \end{array}\right)
C=matrix(QQ, 3, 3, [1, 0, 0, 38, 2, -5, -23, -1, 3]) D=matrix(QQ, 3, 3, [0, 8, -7, 1, 18, -16, 0, -9, 8]) E=matrix(QQ, 3, 3, [465, 23, -61, 1053, 52, -138, -526, -26, 69]) DC=D*C print DC print print E print print DC==E
 [ 465 23 -61] [1053 52 -138] [-526 -26 69] [ 465 23 -61] [1053 52 -138] [-526 -26 69] True [ 465 23 -61] [1053 52 -138] [-526 -26 69] [ 465 23 -61] [1053 52 -138] [-526 -26 69] True