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If reach element of a 3xx3 matrix is mul...

If reach element of a `3xx3` matrix is multiplied by 3, then the determine of the newly formed matrix is

A

`3|A|`

B

`9|A|`

C

`27|A|`

D

`|A|^(3)`

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The correct Answer is:
To find the determinant of a newly formed matrix when each element of a \(3 \times 3\) matrix is multiplied by 3, we can follow these steps: ### Step-by-Step Solution: 1. **Let the original matrix be \(A\)**: \[ A = \begin{pmatrix} a_{11} & a_{12} & a_{13} \\ a_{21} & a_{22} & a_{23} \\ a_{31} & a_{32} & a_{33} \end{pmatrix} \] 2. **Multiply each element of the matrix \(A\) by 3**: \[ 3A = \begin{pmatrix} 3a_{11} & 3a_{12} & 3a_{13} \\ 3a_{21} & 3a_{22} & 3a_{23} \\ 3a_{31} & 3a_{32} & 3a_{33} \end{pmatrix} \] 3. **Use the property of determinants**: The determinant of a matrix that has been multiplied by a scalar \(k\) can be expressed as: \[ \text{det}(kA) = k^n \cdot \text{det}(A) \] where \(n\) is the order of the matrix. In this case, since we have a \(3 \times 3\) matrix, \(n = 3\). 4. **Substituting the values**: Here, \(k = 3\) and \(n = 3\): \[ \text{det}(3A) = 3^3 \cdot \text{det}(A) = 27 \cdot \text{det}(A) \] 5. **Conclusion**: Therefore, the determinant of the newly formed matrix \(3A\) is: \[ \text{det}(3A) = 27 \cdot \text{det}(A) \]
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ML KHANNA-MATRICES-PROBLEM SET(1) (MULTIPLE CHOICE QUESTIONS)
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