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Complete question:

Consider the matrix A given by


A = [[-3,-2,2] , [1, 3 ,1] , [4 , 4, -1]]


Find the inverse of A

User Msevgi
by
7.6k points

1 Answer

1 vote

Answer:

The inverse of the matrix A is:

A^-1 = [[-1/7 10/49 -6/49] , [-18/49 -3/49 22/147] , [5/7 -2/49 -1/49]]

Step-by-step explanation:

To find the inverse of matrix A, we need to follow the following steps:

Step 1: Calculate the determinant of matrix A

det(A) = |-3 -2 2|

| 1 3 1|

| 4 4 -1|

= -3(3(-1) - 4(1)) - 2(1(-1) - 4(2)) + 2(1(4) - 3(4)

= -7

Step 2: Find the adjugate of A, which is the transpose of the matrix of cofactors of A

Adj(A) = [Cof(A)]^T

Cof(A) = [[ 7 18 -10] , [-10 -11 10] , [ 4 14 -7]]

Adj(A) = [[ 7 -10 4] , [18 -11 14] , [-10 10 -7]]

Step 3: Compute the inverse of A using the formula:

A^-1 = (1/det(A)) * Adj(A)

A^-1 = (1/-7) * [[ 7 -10 4] , [18 -11 14] , [-10 10 -7]]

A^-1 = [[-1/7 10/49 -6/49] , [-18/49 -3/49 22/147] , [5/7 -2/49 -1/49]]

Therefore, the inverse of matrix A is:

A^-1 = [[-1/7 10/49 -6/49] , [-18/49 -3/49 22/147] , [5/7 -2/49 -1/49]]

Hope this helped, sorry if it didn't. If you need more help, ask me! :]

User Akarca
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