Answer :
To determine whether two matrices are inverses of each other, we need to check if their product is the identity matrix. We start with the given matrices:
[tex]\[ A = \left[\begin{array}{rrr} 1 & -1 & 1 \\ 0 & 3 & -1 \\ 3 & 7 & 0 \end{array}\right] \][/tex]
[tex]\[ B = \left[\begin{array}{rrr} 7 & 7 & -2 \\ -3 & -3 & 1 \\ -9 & -10 & 3 \end{array}\right] \][/tex]
The identity matrix for a 3x3 matrix is:
[tex]\[ I = \left[\begin{array}{rrr} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{array}\right] \][/tex]
We need to compute the product [tex]\(AB\)[/tex]:
[tex]\[ AB = \left[\begin{array}{rrr} 1 & -1 & 1 \\ 0 & 3 & -1 \\ 3 & 7 & 0 \end{array}\right] \left[\begin{array}{rrr} 7 & 7 & -2 \\ -3 & -3 & 1 \\ -9 & -10 & 3 \end{array}\right] \][/tex]
After calculating the matrix product, we get:
[tex]\[ AB = \left[\begin{array}{rrr} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{array}\right] \][/tex]
The product [tex]\(AB\)[/tex] is clearly the identity matrix [tex]\(I\)[/tex]. Therefore, the given matrices [tex]\(A\)[/tex] and [tex]\(B\)[/tex] are inverses of each other.
So, the answer to the question "Are the matrices inverses of each other?" is:
Yes
[tex]\[ A = \left[\begin{array}{rrr} 1 & -1 & 1 \\ 0 & 3 & -1 \\ 3 & 7 & 0 \end{array}\right] \][/tex]
[tex]\[ B = \left[\begin{array}{rrr} 7 & 7 & -2 \\ -3 & -3 & 1 \\ -9 & -10 & 3 \end{array}\right] \][/tex]
The identity matrix for a 3x3 matrix is:
[tex]\[ I = \left[\begin{array}{rrr} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{array}\right] \][/tex]
We need to compute the product [tex]\(AB\)[/tex]:
[tex]\[ AB = \left[\begin{array}{rrr} 1 & -1 & 1 \\ 0 & 3 & -1 \\ 3 & 7 & 0 \end{array}\right] \left[\begin{array}{rrr} 7 & 7 & -2 \\ -3 & -3 & 1 \\ -9 & -10 & 3 \end{array}\right] \][/tex]
After calculating the matrix product, we get:
[tex]\[ AB = \left[\begin{array}{rrr} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{array}\right] \][/tex]
The product [tex]\(AB\)[/tex] is clearly the identity matrix [tex]\(I\)[/tex]. Therefore, the given matrices [tex]\(A\)[/tex] and [tex]\(B\)[/tex] are inverses of each other.
So, the answer to the question "Are the matrices inverses of each other?" is:
Yes