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Find the matrix \({\mathrm{A}}^{2}\), where \(\mathrm{A}=\left[{a}_{ij}\right]\) is a \(2\times 2\) matrix whose element…

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Find the matrix \({\mathrm{A}}^{2}\), where \(\mathrm{A}=\left[{a}_{ij}\right]\) is a \(2\times 2\) matrix whose elements are given by \({a}_{ij}=maximum(\mathrm{i},\mathrm{j})-minimum(\mathrm{i},\mathrm{j})\) :

a

\(\left[\begin{matrix}0 & 0 \\ 0 & 0\end{matrix}\right]\)

b

\(\left[\begin{matrix}0 & 1 \\ 1 & 0\end{matrix}\right]\)

c

\(\left[\begin{matrix}1 & 0 \\ 0 & 1\end{matrix}\right]\)

d

\(\left[\begin{matrix}1 & 1 \\ 1 & 1\end{matrix}\right]\)

✓ Correct answer: c)

\(\left[\begin{matrix}1 & 0 \\ 0 & 1\end{matrix}\right]\)

Explanation

Given: \({a}_{ij}=\max (i,j)-\min (i,j)\)

So,

\({a}_{11}=\max (1,1)-\min (1,1)=1-1=0,\\ {a}_{12}=\max (1,2)-\min (1,2)=2-1=1,\\ {a}_{21}=\max (2,1)-\min (2,1)=2-1=1,\\ {a}_{22}=\max (2,2)-\min (2,2)=2-2=0\)

The matrix \(A\) is: \(A=\left[\begin{matrix}0 & 1 \\ 1 & 0\end{matrix}\right]\)

Hence,

\({A}^{2}=A\times A\\ =\left[\begin{matrix}0 & 1 \\ 1 & 0\end{matrix}\right]\times \left[\begin{matrix}0 & 1 \\ 1 & 0\end{matrix}\right]\\ =\left[\begin{matrix}1 & 0 \\ 0 & 1\end{matrix}\right]\)

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