JEE Mains · Maths · STD 12 - 3 and 4 . metrices and determinant
If \(A = \left[ {\begin{array}{*{20}{c}}1&2&2\\2&1&{ - 2}\\a&2&b\end{array}} \right]\) is a matrix satisfying the equation \(AA^T=9I \) where\( I\) is \(3×3\) identity matrix, then the ordered pair \((a, b)\) is equal to:
- A \((-2,-1)\)
- B \((2,-1)\)
- C \((-2,1)\)
- D \((2,1)\)
Answer & Solution
Correct Answer
(A) \((-2,-1)\)
Step-by-step Solution
Detailed explanation
\({{\rm{A}}{{\rm{A}}^ \top } = 9{\rm{I}}}\)…
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