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The Matrix a = ⎡ ⎢ ⎣ 0 − 5 8 5 0 12 − 8 − 12 0 ⎤ ⎥ ⎦ is a - Mathematics

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Question

The matrix  \[A = \begin{bmatrix}0 & - 5 & 8 \\ 5 & 0 & 12 \\ - 8 & - 12 & 0\end{bmatrix}\] is a 

 

Options

  • diagonal matrix

  • symmetric matrix

  • skew-symmetric matrix

  • scalar matrix

MCQ
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Solution

Given:  

\[A = \begin{bmatrix}0 & - 5 & 8 \\ 5 & 0 & 12 \\ - 8 & - 12 & 0\end{bmatrix}\]

\[A^T = \begin{bmatrix}0 & - 5 & 8 \\ 5 & 0 & 12 \\ - 8 & - 12 & 0\end{bmatrix}^T \] 

\[ = \begin{bmatrix}0 & 5 & - 8 \\ - 5 & 0 & - 12 \\ 8 & 12 & 0\end{bmatrix}\] 

\[ = - 1\begin{bmatrix}0 & - 5 & 8 \\ 5 & 0 & 12 \\ - 8 & - 12 & 0\end{bmatrix}\] 

\[ = - A\]

Therefore, matrix A is skew-symmetric matrix.

Hence, the correct option is (c).

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Chapter 5: Algebra of Matrices - Exercise 5.7 [Page 69]

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RD Sharma Mathematics [English] Class 12
Chapter 5 Algebra of Matrices
Exercise 5.7 | Q 44 | Page 69

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