If A = [ * 20 c 4&2 3&4 ],then |adj , ,A|is equal to - Vidyadip

MCQ

If $A = \left[ {\begin{array}{*{20}{c}}4&2\\3&4\end{array}} \right]$,then $|adj\,\,A|$is equal to

A
$16$
✓
$10$
C
$6$
D
None of these

✓

Answer

Correct option: B.

$10$

b
(b) $A = \left[ {\begin{array}{*{20}{c}}4&{ 2}\\{ 3}&4\end{array}} \right]$

adj $A = \left[ {\begin{array}{*{20}{c}}4&{ - 2}\\{ - 3}&4\end{array}} \right]$

$|adj\,A|\, = (4 \times 4) - ( - 3 \times - 2) = 16 - 6$

$|adj\,A|\,\, = 10.$

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