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Matrices and Determinants question

2025 · 24 Jan · Shift 1 · Q46
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Matrices and Determinants question

2025 · 24 Jan · Shift 1 · Q46

JEE MainMathematicsMatrices and DeterminantsNumerical+4 / −1
Let A be a 3×33 \times 33×3 matrix such that XTAX=O\mathrm{X}^{\mathrm{T}} \mathrm{AX}=\mathrm{O}XTAX=O for all nonzero 3×13 \times 13×1 matrices X=[xyz]X=\left[\begin{array}{l}x \\ y \\ z\end{array}\right]X=​xyz​​. If A[111]=[14−5],A[121]=[04−8]\mathrm{A}\left[\begin{array}{l}1 \\ 1 \\ 1\end{array}\right]=\left[\begin{array}{c}1 \\ 4 \\ -5\end{array}\right], \mathrm{A}\left[\begin{array}{l}1 \\ 2 \\ 1\end{array}\right]=\left[\begin{array}{c}0 \\ 4 \\ -8\end{array}\right]A​111​​=​14−5​​,A​121​​=​04−8​​, and det⁡(adj⁡(2( A+I)))=2α3β5γ,α,β,γ∈N\operatorname{det}(\operatorname{adj}(2(\mathrm{~A}+\mathrm{I})))=2^\alpha 3^\beta 5^\gamma, \alpha, \beta, \gamma \in Ndet(adj(2( A+I)))=2α3β5γ,α,β,γ∈N, then α2+β2+γ2\alpha^2+\beta^2+\gamma^2α2+β2+γ2 is
Numerical answer
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