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Find the inverse of the matrix, use an algorithm for finding A^-1 by row reducing [A I]

[------------------]

| 1 0 -3 | 1 0 0 |

| 3 1 -4 | 0 1 0 |

| 4 2 -4 | 0 0 1 |

[------------------]

User Oschlueter
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2 Answers

5 votes

Answer:

To find the inverse of the matrix A, we will use the row reduction method. We will augment matrix A with the identity matrix I and perform row operations until A is transformed into the identity matrix. The resulting matrix on the right side will be the inverse of A.

Explanation:

Augment the matrix A with the identity matrix I:

[ 1 0 -3 | 1 0 0 ]

[ 3 1 -4 | 0 1 0 ]

[ 4 2 -4 | 0 0 1 ]

Perform row operations to transform the left side of the augmented matrix into the identity matrix:

R2 = R2 - 3R1

R3 = R3 - 4R1

[ 1 0 -3 | 1 0 0 ]

[ 0 1 5 | -3 1 0 ]

[ 0 2 8 | -4 0 1 ]

Perform row operations to further transform the left side of the augmented matrix into the identity matrix:

R3 = R3 - 2R2

[ 1 0 -3 | 1 0 0 ]

[ 0 1 5 | -3 1 0 ]

[ 0 0 -2 | 2 -2 1 ]

Multiply the third row by -1/2 to make the pivot element of the third row equal to 1:

R3 = (-1/2) * R3

[ 1 0 -3 | 1 0 0 ]

[ 0 1 5 | -3 1 0 ]

[ 0 0 1 | -1 1 -1/2 ]

Perform row operations to further transform the left side of the augmented matrix into the identity matrix:

R1 = R1 + 3R3

R2 = R2 - 5R3

[ 1 0 0 | 2 0 3/2 ]

[ 0 1 0 | 2 -4 5/2 ]

[ 0 0 1 | -1 1 -1/2 ]

The resulting matrix on the right side of the augmented matrix is the inverse of matrix A:

[ 2 0 3/2 ]

[ 2 -4 5/2 ]

[ -1 1 -1/2 ]

Therefore, the inverse of matrix A is:

[ 2 0 3/2 ]

[ 2 -4 5/2 ]

[ -1 1 -1/2 ]

User Jimmygchen
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7.9k points
5 votes

Answer:

A: A^-1 = [[-2,-3,-1.5],[-2,-4,-2.5],[-1,1,-.5]]

Explanation:

User Dr Fabio Gori
by
7.5k points

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