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If a = [ I 0 0 I ] , Write A2. - Mathematics

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Question

If  \[A = \begin{bmatrix}i & 0 \\ 0 & i\end{bmatrix}\] , write A2.
 

 

Sum
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Solution

\[Given: A = \begin{bmatrix}i & 0 \\ 0 & i\end{bmatrix}\] 

\[ A^2 = AA\] 

\[ \Rightarrow A^2 = \begin{bmatrix}i & 0 \\ 0 & i\end{bmatrix}\begin{bmatrix}i & 0 \\ 0 & i\end{bmatrix}\] 

\[ \Rightarrow A^2 = \begin{bmatrix}i^2 + 0 & 0 + 0 \\ 0 + 0 & 0 + i^2\end{bmatrix}\] 

\[ \Rightarrow A^2 = \begin{bmatrix}i^2 & 0 \\ 0 & i^2\end{bmatrix}\] 

\[ \Rightarrow A^2 = \begin{bmatrix}- 1 & 0 \\ 0 & - 1\end{bmatrix} \left( \because i^2 = - 1 \right)\] 

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Chapter 5: Algebra of Matrices - Exercise 5.6 [Page 62]

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RD Sharma Mathematics [English] Class 12
Chapter 5 Algebra of Matrices
Exercise 5.6 | Q 7 | Page 62

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