If $A = \left[ {\begin{array}{*{20}{c}} 2&{ - 1}\\ { - 1}&2 \end{array}} \right]$ and $i$ is the unit matrix of order 2, then ${A^2}\;$ equals

JEE MATHEMATICS MCQ: MATRICES

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Application +4 | -1

A = \left[ {\begin{array}{cccccccccccccccccccc} 2&{ - 1}\\ { - 1}&2 \end{array}} \right]

and

i

is the unit matrix of order 2, then

{A^2}\;

equals

View answer and explanation

Correct option: A

4A - 3I

Option A (4A - 3I) is correct because when A is squared, it results in 4A - 3I, which can be verified through matrix multiplication and simplification.

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