Differential Equations and Linear Algebra (4th Edition)

Published by Pearson
ISBN 10: 0-32196-467-5
ISBN 13: 978-0-32196-467-0

Chapter 2 - Matrices and Systems of Linear Equations - 2.4 Row-Echelon Matrices and Elementary Row Operations - Problems - Page 156: 13

Answer

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Work Step by Step

$\begin{bmatrix} 2 & -1 &3\\ 3 & 1 & -2 \\ 2 &-2 &1 \end{bmatrix} \approx^1 \begin{bmatrix} 3 & 1 &-2\\ 2 & -1 & 3 \\ 2 &-2 &1 \end{bmatrix} \approx^2 \begin{bmatrix} 1 & 2 &-5\\ 2 & -1 & 3 \\ 0 &-1 &-2 \end{bmatrix} \approx^3\begin{bmatrix} 1 & 2 &-5\\ 0 & -5 & 13 \\ 0 &-1 &-2 \end{bmatrix} \approx^4 \begin{bmatrix} 1 & 2 &-5\\ 0 & -1 & -2 \\ 0 &-5 &13 \end{bmatrix} \approx^5 \begin{bmatrix} 1 & 2 &-5\\ 0 & 1 & 2 \\ 0 &-5 &13 \end{bmatrix} \approx^6 \begin{bmatrix} 1 & 2 &-5\\ 0 & 1 & 2 \\ 0 &0 &23 \end{bmatrix} \approx^7 \begin{bmatrix} 1 & 2 &-5\\ 0 & 1 & 2 \\ 0 &0 &1 \end{bmatrix}$ Rank (A) =3 The rank of each matrix: $P_{12}$ $A_{21}(-1), A_{23}(-1)$ $A_{12}(-2)$ $A_{13}(-3)$ $P_{23}$ $M_{2}(-1)$ $A_{23}(5)$ $M_{3}(\frac{1}{23})$
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