If A= [ r 1 -4 3 ] and B= [ lll -1 & 2 & 1 ], then (A B)^ is equal to

A. [ rrr -1 & 4 & -3 2 & -8 & 6 1 & -4 & 3 ]

If A= [ r 1 -4 3 ] and B= [ lll -1 & 2 & 1 ], then (A B)^ is equa…

MCQ

If $A=\left[\begin{array}{r}1 \\ -4 \\ 3\end{array}\right]$ and $B=\left[\begin{array}{lll}-1 & 2 & 1\end{array}\right]$, then $(A B)^{\prime}$ is equal to

✓
$\left[\begin{array}{rrr}-1 & 4 & -3 \\ 2 & -8 & 6 \\ 1 & -4 & 3\end{array}\right]$
B
$\left[\begin{array}{rrr}-1 & 2 & 1 \\ 4 & -8 & -4 \\ -3 & 6 & 3\end{array}\right]$
C
$\left[\begin{array}{rrr}1 & 4 & -3 \\ 2 & -8 & 6 \\ 1 & 4 & 3\end{array}\right]$
D
$\left[\begin{array}{rrr}-1 & 4 & -3 \\ 2 & 8 & 6 \\ 1 & -4 & 3\end{array}\right]$

✓

Answer

Correct option: A.

$\left[\begin{array}{rrr}-1 & 4 & -3 \\ 2 & -8 & 6 \\ 1 & -4 & 3\end{array}\right]$

(a) : $(A B)=\left[\begin{array}{c}1 \\ -4 \\ 3\end{array}\right]\left[\begin{array}{lll}-1 & 2 & 1\end{array}\right]=\left[\begin{array}{ccc}-1 & 2 & 1 \\ 4 & -8 & -4 \\ -3 & 6 & 3\end{array}\right]$
$
\therefore \quad(A B)^{\prime}=\left[\begin{array}{ccc}
-1 & 4 & -3 \\
2 & -8 & 6 \\
1 & -4 & 3
\end{array}\right]
$

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