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Mathematics · 2024 · 1 mark
CBSE 2024 · Region 1 · Set 2 · Q6
If a_ij and A_ij represent the (ij)th element and its cofactor of [2, -3, 5; 6, 0, 4; 1, 5, -7] respectively, then the value of a_11 A_21+ a_12 A_22+…
If $\displaystyle \mathrm{a}_{\mathrm{ij}}$ and $\displaystyle \mathrm{A}_{\mathrm{ij}}$ represent the (ij)th element and its cofactor of $\displaystyle \left[\begin{array}{rrr}2 & -3 & 5 \\ 6 & 0 & 4 \\ 1 & 5 & -7\end{array}\right]$ respectively, then the value of $\displaystyle \mathrm{a}_{11} \mathrm{A}_{21}+\mathrm{a}_{12} \mathrm{A}_{22}+\mathrm{a}_{13} \mathrm{A}_{23}$ is :
Official answer
(A)
$\displaystyle 0$
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CBSE Class 12 Mathematics past-paper question from the 2024 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.