Question bank/JEE Main/Mathematics
JEE MainMathematicsToughMatrix and determinants
Let is a square matrix of order 2 where a_ij
then number of matrices A such that A^-1 exists is
then - 300 is (given that all elements of matrix A
are distinct)
Show answer and solution
For A^-1 exists
Case - I: Exactly one element is zero
Case - ll: No element is zero
$A = \left| \begin{matrix}
a\ \ \ \ b \\
c\ \ \ \ d
\end{matrix} \right|$
= ad - bc = 0 ad = bc = 6
ad = bc = 12
= 104
Total = 344

Case - I: Exactly one element is zero
Case - ll: No element is zero
$A = \left| \begin{matrix}
a\ \ \ \ b \\
c\ \ \ \ d
\end{matrix} \right|$
= ad - bc = 0 ad = bc = 6
ad = bc = 12
= 104
Total = 344

Source: Grass-G / M-23 Mathematics Paper 31 Dec FST.docx
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