If A = ( * 20 c 2& - 1 - 7 &4 ) and B = ( * 20 c 4&1 7&2 ) then which of the following is correct

If A = ( * 20 c 2& - 1 - 7 &4 ) and B = ( * 20 c 4&1 7&2 ) then w…

MCQ

If $A = \left( {\begin{array}{*{20}{c}}
2&{ - 1}\\
{ - 7}&4
\end{array}} \right)$ and $B = \left( {\begin{array}{*{20}{c}}
4&1\\
7&2
\end{array}} \right)$ then which of the following is correct

A
$AA^T = I$
✓
$(AB)^T = I$
C
$BB^T = I$
D
$AB \neq BA$

✓

Answer

Correct option: B.

$(AB)^T = I$

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