Adjoint and Inverse of Matrices
Matrix and Determinant

78892 If \(A=\left[\begin{array}{ccc}1 & 2 & 3 \\ 1 & 1 & 1 \\ 1 & -1 & 1\end{array}\right], B=\left[\begin{array}{lll}1 & 1 & 0 \\ 0 & 1 & 3 \\ 3 & 0 & 4\end{array}\right]\)
\(\mathbf{C}=\left[\begin{array}{lll}2 & 0 & 1 \\ 0 & 1 & 0 \\ 3 & 2 & 1\end{array}\right], \operatorname{then}\left(\left(\left((A B C)^{-1}\right)^{\mathrm{T}}\right)^{-1}\right)^{\mathrm{T}}=\)

1 \(\left[\begin{array}{ccc}64 & 39 & 28 \\ 29 & 16 & 11 \\ 11 & 2 & 5\end{array}\right]\)
2 \(\left[\begin{array}{ccc}63 & 39 & 20 \\ 29 & 16 & 11 \\ 10 & 2 & 5\end{array}\right]\)
3 \(\left[\begin{array}{ccc}64 & 39 & 27 \\ 28 & 15 & 11 \\ 11 & 2 & 5\end{array}\right]\)
4 \(\left[\begin{array}{ccc}61 & 39 & 28 \\ 29 & 16 & 11 \\ 11 & 0 & 5\end{array}\right]\)
Matrix and Determinant

78893 Let \(A, B, C, D\) be square real matrices such that \(\mathbf{C}^{\mathrm{T}}=\mathrm{DAB}, \mathrm{D}^{\mathrm{T}}=\mathrm{ABC}, \mathrm{S}=\mathrm{ABCD}\) then \(\mathrm{S}^{2}\) is equal to

1 \(\mathrm{S}\)
2 \(BCD\)
3 \(S^{\mathrm{T}}\)
4 \(\left(\mathrm{S}^{\mathrm{T}}\right)^{2}=\left(\mathrm{S}^{2}\right)^{\mathrm{T}}\)
Matrix and Determinant

78895 The value of \(\left|\begin{array}{ccc}x+y & y+z & z+x \\ x & y & z \\ x-y & y-z & z-x\end{array}\right|\) is equal to :

1 \(2(x+y+z)^{2}\)
2 \(2(x+y+z)^{3}\)
3 \((x+y+z)^{3}\)
4 0
Matrix and Determinant

78896 Let \(A=\left[\begin{array}{ccc}1 & -1 & 1 \\ 2 & 1 & -3 \\ 1 & 1 & 1\end{array}\right]\) and \(10 B=\left[\begin{array}{ccc}4 & 2 & 2 \\ -5 & 0 & \alpha \\ 1 & -2 & 3\end{array}\right]\).If
\(B\) is the inverse of matrix \(A\), then \(\alpha\) is

1 -1
2 -2
3 2
4 5
Matrix and Determinant

78899 Let \(A=\left(\begin{array}{ll}1 & 2 \\ 2 & 1\end{array}\right) . \quad\) The determinant of \(\frac{1}{3} \mathrm{~A}(\operatorname{adj}(\operatorname{adj} \mathrm{A}))\) is

1 1
2 -1
3 \(1 / 3\)
4 3
Matrix and Determinant

78892 If \(A=\left[\begin{array}{ccc}1 & 2 & 3 \\ 1 & 1 & 1 \\ 1 & -1 & 1\end{array}\right], B=\left[\begin{array}{lll}1 & 1 & 0 \\ 0 & 1 & 3 \\ 3 & 0 & 4\end{array}\right]\)
\(\mathbf{C}=\left[\begin{array}{lll}2 & 0 & 1 \\ 0 & 1 & 0 \\ 3 & 2 & 1\end{array}\right], \operatorname{then}\left(\left(\left((A B C)^{-1}\right)^{\mathrm{T}}\right)^{-1}\right)^{\mathrm{T}}=\)

1 \(\left[\begin{array}{ccc}64 & 39 & 28 \\ 29 & 16 & 11 \\ 11 & 2 & 5\end{array}\right]\)
2 \(\left[\begin{array}{ccc}63 & 39 & 20 \\ 29 & 16 & 11 \\ 10 & 2 & 5\end{array}\right]\)
3 \(\left[\begin{array}{ccc}64 & 39 & 27 \\ 28 & 15 & 11 \\ 11 & 2 & 5\end{array}\right]\)
4 \(\left[\begin{array}{ccc}61 & 39 & 28 \\ 29 & 16 & 11 \\ 11 & 0 & 5\end{array}\right]\)
Matrix and Determinant

78893 Let \(A, B, C, D\) be square real matrices such that \(\mathbf{C}^{\mathrm{T}}=\mathrm{DAB}, \mathrm{D}^{\mathrm{T}}=\mathrm{ABC}, \mathrm{S}=\mathrm{ABCD}\) then \(\mathrm{S}^{2}\) is equal to

1 \(\mathrm{S}\)
2 \(BCD\)
3 \(S^{\mathrm{T}}\)
4 \(\left(\mathrm{S}^{\mathrm{T}}\right)^{2}=\left(\mathrm{S}^{2}\right)^{\mathrm{T}}\)
Matrix and Determinant

78895 The value of \(\left|\begin{array}{ccc}x+y & y+z & z+x \\ x & y & z \\ x-y & y-z & z-x\end{array}\right|\) is equal to :

1 \(2(x+y+z)^{2}\)
2 \(2(x+y+z)^{3}\)
3 \((x+y+z)^{3}\)
4 0
Matrix and Determinant

78896 Let \(A=\left[\begin{array}{ccc}1 & -1 & 1 \\ 2 & 1 & -3 \\ 1 & 1 & 1\end{array}\right]\) and \(10 B=\left[\begin{array}{ccc}4 & 2 & 2 \\ -5 & 0 & \alpha \\ 1 & -2 & 3\end{array}\right]\).If
\(B\) is the inverse of matrix \(A\), then \(\alpha\) is

1 -1
2 -2
3 2
4 5
Matrix and Determinant

78899 Let \(A=\left(\begin{array}{ll}1 & 2 \\ 2 & 1\end{array}\right) . \quad\) The determinant of \(\frac{1}{3} \mathrm{~A}(\operatorname{adj}(\operatorname{adj} \mathrm{A}))\) is

1 1
2 -1
3 \(1 / 3\)
4 3
Matrix and Determinant

78892 If \(A=\left[\begin{array}{ccc}1 & 2 & 3 \\ 1 & 1 & 1 \\ 1 & -1 & 1\end{array}\right], B=\left[\begin{array}{lll}1 & 1 & 0 \\ 0 & 1 & 3 \\ 3 & 0 & 4\end{array}\right]\)
\(\mathbf{C}=\left[\begin{array}{lll}2 & 0 & 1 \\ 0 & 1 & 0 \\ 3 & 2 & 1\end{array}\right], \operatorname{then}\left(\left(\left((A B C)^{-1}\right)^{\mathrm{T}}\right)^{-1}\right)^{\mathrm{T}}=\)

1 \(\left[\begin{array}{ccc}64 & 39 & 28 \\ 29 & 16 & 11 \\ 11 & 2 & 5\end{array}\right]\)
2 \(\left[\begin{array}{ccc}63 & 39 & 20 \\ 29 & 16 & 11 \\ 10 & 2 & 5\end{array}\right]\)
3 \(\left[\begin{array}{ccc}64 & 39 & 27 \\ 28 & 15 & 11 \\ 11 & 2 & 5\end{array}\right]\)
4 \(\left[\begin{array}{ccc}61 & 39 & 28 \\ 29 & 16 & 11 \\ 11 & 0 & 5\end{array}\right]\)
Matrix and Determinant

78893 Let \(A, B, C, D\) be square real matrices such that \(\mathbf{C}^{\mathrm{T}}=\mathrm{DAB}, \mathrm{D}^{\mathrm{T}}=\mathrm{ABC}, \mathrm{S}=\mathrm{ABCD}\) then \(\mathrm{S}^{2}\) is equal to

1 \(\mathrm{S}\)
2 \(BCD\)
3 \(S^{\mathrm{T}}\)
4 \(\left(\mathrm{S}^{\mathrm{T}}\right)^{2}=\left(\mathrm{S}^{2}\right)^{\mathrm{T}}\)
Matrix and Determinant

78895 The value of \(\left|\begin{array}{ccc}x+y & y+z & z+x \\ x & y & z \\ x-y & y-z & z-x\end{array}\right|\) is equal to :

1 \(2(x+y+z)^{2}\)
2 \(2(x+y+z)^{3}\)
3 \((x+y+z)^{3}\)
4 0
Matrix and Determinant

78896 Let \(A=\left[\begin{array}{ccc}1 & -1 & 1 \\ 2 & 1 & -3 \\ 1 & 1 & 1\end{array}\right]\) and \(10 B=\left[\begin{array}{ccc}4 & 2 & 2 \\ -5 & 0 & \alpha \\ 1 & -2 & 3\end{array}\right]\).If
\(B\) is the inverse of matrix \(A\), then \(\alpha\) is

1 -1
2 -2
3 2
4 5
Matrix and Determinant

78899 Let \(A=\left(\begin{array}{ll}1 & 2 \\ 2 & 1\end{array}\right) . \quad\) The determinant of \(\frac{1}{3} \mathrm{~A}(\operatorname{adj}(\operatorname{adj} \mathrm{A}))\) is

1 1
2 -1
3 \(1 / 3\)
4 3
Matrix and Determinant

78892 If \(A=\left[\begin{array}{ccc}1 & 2 & 3 \\ 1 & 1 & 1 \\ 1 & -1 & 1\end{array}\right], B=\left[\begin{array}{lll}1 & 1 & 0 \\ 0 & 1 & 3 \\ 3 & 0 & 4\end{array}\right]\)
\(\mathbf{C}=\left[\begin{array}{lll}2 & 0 & 1 \\ 0 & 1 & 0 \\ 3 & 2 & 1\end{array}\right], \operatorname{then}\left(\left(\left((A B C)^{-1}\right)^{\mathrm{T}}\right)^{-1}\right)^{\mathrm{T}}=\)

1 \(\left[\begin{array}{ccc}64 & 39 & 28 \\ 29 & 16 & 11 \\ 11 & 2 & 5\end{array}\right]\)
2 \(\left[\begin{array}{ccc}63 & 39 & 20 \\ 29 & 16 & 11 \\ 10 & 2 & 5\end{array}\right]\)
3 \(\left[\begin{array}{ccc}64 & 39 & 27 \\ 28 & 15 & 11 \\ 11 & 2 & 5\end{array}\right]\)
4 \(\left[\begin{array}{ccc}61 & 39 & 28 \\ 29 & 16 & 11 \\ 11 & 0 & 5\end{array}\right]\)
Matrix and Determinant

78893 Let \(A, B, C, D\) be square real matrices such that \(\mathbf{C}^{\mathrm{T}}=\mathrm{DAB}, \mathrm{D}^{\mathrm{T}}=\mathrm{ABC}, \mathrm{S}=\mathrm{ABCD}\) then \(\mathrm{S}^{2}\) is equal to

1 \(\mathrm{S}\)
2 \(BCD\)
3 \(S^{\mathrm{T}}\)
4 \(\left(\mathrm{S}^{\mathrm{T}}\right)^{2}=\left(\mathrm{S}^{2}\right)^{\mathrm{T}}\)
Matrix and Determinant

78895 The value of \(\left|\begin{array}{ccc}x+y & y+z & z+x \\ x & y & z \\ x-y & y-z & z-x\end{array}\right|\) is equal to :

1 \(2(x+y+z)^{2}\)
2 \(2(x+y+z)^{3}\)
3 \((x+y+z)^{3}\)
4 0
Matrix and Determinant

78896 Let \(A=\left[\begin{array}{ccc}1 & -1 & 1 \\ 2 & 1 & -3 \\ 1 & 1 & 1\end{array}\right]\) and \(10 B=\left[\begin{array}{ccc}4 & 2 & 2 \\ -5 & 0 & \alpha \\ 1 & -2 & 3\end{array}\right]\).If
\(B\) is the inverse of matrix \(A\), then \(\alpha\) is

1 -1
2 -2
3 2
4 5
Matrix and Determinant

78899 Let \(A=\left(\begin{array}{ll}1 & 2 \\ 2 & 1\end{array}\right) . \quad\) The determinant of \(\frac{1}{3} \mathrm{~A}(\operatorname{adj}(\operatorname{adj} \mathrm{A}))\) is

1 1
2 -1
3 \(1 / 3\)
4 3
Matrix and Determinant

78892 If \(A=\left[\begin{array}{ccc}1 & 2 & 3 \\ 1 & 1 & 1 \\ 1 & -1 & 1\end{array}\right], B=\left[\begin{array}{lll}1 & 1 & 0 \\ 0 & 1 & 3 \\ 3 & 0 & 4\end{array}\right]\)
\(\mathbf{C}=\left[\begin{array}{lll}2 & 0 & 1 \\ 0 & 1 & 0 \\ 3 & 2 & 1\end{array}\right], \operatorname{then}\left(\left(\left((A B C)^{-1}\right)^{\mathrm{T}}\right)^{-1}\right)^{\mathrm{T}}=\)

1 \(\left[\begin{array}{ccc}64 & 39 & 28 \\ 29 & 16 & 11 \\ 11 & 2 & 5\end{array}\right]\)
2 \(\left[\begin{array}{ccc}63 & 39 & 20 \\ 29 & 16 & 11 \\ 10 & 2 & 5\end{array}\right]\)
3 \(\left[\begin{array}{ccc}64 & 39 & 27 \\ 28 & 15 & 11 \\ 11 & 2 & 5\end{array}\right]\)
4 \(\left[\begin{array}{ccc}61 & 39 & 28 \\ 29 & 16 & 11 \\ 11 & 0 & 5\end{array}\right]\)
Matrix and Determinant

78893 Let \(A, B, C, D\) be square real matrices such that \(\mathbf{C}^{\mathrm{T}}=\mathrm{DAB}, \mathrm{D}^{\mathrm{T}}=\mathrm{ABC}, \mathrm{S}=\mathrm{ABCD}\) then \(\mathrm{S}^{2}\) is equal to

1 \(\mathrm{S}\)
2 \(BCD\)
3 \(S^{\mathrm{T}}\)
4 \(\left(\mathrm{S}^{\mathrm{T}}\right)^{2}=\left(\mathrm{S}^{2}\right)^{\mathrm{T}}\)
Matrix and Determinant

78895 The value of \(\left|\begin{array}{ccc}x+y & y+z & z+x \\ x & y & z \\ x-y & y-z & z-x\end{array}\right|\) is equal to :

1 \(2(x+y+z)^{2}\)
2 \(2(x+y+z)^{3}\)
3 \((x+y+z)^{3}\)
4 0
Matrix and Determinant

78896 Let \(A=\left[\begin{array}{ccc}1 & -1 & 1 \\ 2 & 1 & -3 \\ 1 & 1 & 1\end{array}\right]\) and \(10 B=\left[\begin{array}{ccc}4 & 2 & 2 \\ -5 & 0 & \alpha \\ 1 & -2 & 3\end{array}\right]\).If
\(B\) is the inverse of matrix \(A\), then \(\alpha\) is

1 -1
2 -2
3 2
4 5
Matrix and Determinant

78899 Let \(A=\left(\begin{array}{ll}1 & 2 \\ 2 & 1\end{array}\right) . \quad\) The determinant of \(\frac{1}{3} \mathrm{~A}(\operatorname{adj}(\operatorname{adj} \mathrm{A}))\) is

1 1
2 -1
3 \(1 / 3\)
4 3