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The Matrix ⎡ ⎢ ⎣ 0 5 − 7 − 5 0 11 7 − 11 0 ⎤ ⎥ ⎦ is

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Question

The matrix \[\begin{bmatrix}0 & 5 & - 7 \\ - 5 & 0 & 11 \\ 7 & - 11 & 0\end{bmatrix}\] is

Options

  •  a skew-symmetric matrix

  • a symmetric matrix

  • a diagonal matrix

  • an uppertriangular matrix

MCQ
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Solution

 a skew-symmetric matrix 

Here,

  A =

\[\begin{bmatrix}0 & 5 & - 7 \\ - 5 & 0 & 11 \\ 7 & - 11 & 0\end{bmatrix}\]

\[\Rightarrow\]AT = 

\[\begin{bmatrix}0 & - 5 & 7 \\ 5 & 0 & - 11 \\ - 7 & 11 & 0\end{bmatrix}\]

\[\Rightarrow A^T = - \begin{bmatrix}0 & 5 & - 7 \\ - 5 & 0 & 11 \\ 7 & - 11 & 0\end{bmatrix}\]

\[ \Rightarrow A^T = - A\]

Thus, A is a skew-symmetric matrix.

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Chapter 4: Algebra of Matrices - Exercise 5.7 [Page 67]

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R.D. Sharma Mathematics Volume 1 and 2 [English] Class 12
Chapter 4 Algebra of Matrices
Exercise 5.7 | Q 18 | Page 67

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