[ * 20 c 7&1&2 9&2&1 ] , [ l 3 4 5 ] + 2 [ l 4 2 ] is equal to - Vidyadip

MCQ

$\left[ {\begin{array}{*{20}{c}}7&1&2\\9&2&1\end{array}} \right]\,\left[ \begin{array}{l}3\\4\\5\end{array} \right] + 2\left[ \begin{array}{l}4\\2\end{array} \right]$ is equal to

✓
$\left[ \begin{array}{l}43\\44\end{array} \right]$
B
$\left[ \begin{array}{l}43\\45\end{array} \right]$
C
$\left[ \begin{array}{l}45\\44\end{array} \right]$
D
$\left[ \begin{array}{l}44\\45\end{array} \right]$

✓

Answer

Correct option: A.

$\left[ \begin{array}{l}43\\44\end{array} \right]$

a
(a) $\left[ {\begin{array}{*{20}{c}}7&1&2\\9&2&1\end{array}} \right]\,\left[ {\begin{array}{*{20}{c}}3\\4\\5\end{array}} \right]\, = \,\,\left[ {\begin{array}{*{20}{c}}{35}\\{40}\end{array}} \right]$;

$\therefore$ $\left[ {\begin{array}{*{20}{c}}{35}\\{40}\end{array}} \right]\, + \,\left[ {\begin{array}{*{20}{c}}8\\4\end{array}} \right]\, = \,\left[ {\begin{array}{*{20}{c}}{43}\\{44}\end{array}} \right]$.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from 3 and 4 . determinant and metrices→3 and 4 . determinant and metrices — all question types→Maths STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

If ${\Delta _1} = \left| {\,\begin{array}{*{20}{c}}1&0\\a&b\end{array}\,} \right|$ and ${\Delta _2} = \left| {\begin{array}{*{20}{c}}1&0\\c&d\end{array}} \right|$, then ${\Delta _2}{\Delta _1}$is equal to

The solution of the equation $\frac{d y}{d x}=\frac{e^x+e^{-x}}{e^x-e^{-x}}$ is :

All $x$ satisfying the inequality ${\left( {{{\cot }^{ - 1}}\,x} \right)^2} - 7\left( {{{\cot }^{ - 1}}\,x} \right) + 10 > 0$, lie in the interval

Let $A$ is a symmetric and $ \,B$ is a skew symmetric matrix, such that $A - B = \left[ {\begin{array}{*{20}{c}}
1&2 \\
3&4
\end{array}} \right]$, then $|A|$ is

The set of all $\alpha$, for which the vector $\vec{a}=\alpha t \hat{i}+6 \hat{j}-3 \hat{k} \quad$ and $\quad \vec{b}=t \hat{i}-2 \hat{j}-2 \alpha t \hat{k} \quad$ are inclined at an obtuse angle for all $t \in \mathbb{R}$ is :

A closed vessel tapers to a point both at its top $E$ and its bottom $F$ and is fixed with $EF$ vertical when the depth of the liquid in it is $x\,\, cm$, the volume of the liquid in it is, $ x^2 (15 - x) \,\,cu. cm.$ The length $EF$ is ........ $cm $.

Volume of the parallelopiped whose coterminous edges are $2i - 3j + 4k,\,\,i + 2j - 2k,\,\,3i - j + k,$ is ............ $\mathrm{cubic\,unit}$

Assume that $3.13 \leq \pi \leq 15$. The integer closest to the value of $\sin ^{-1}(\sin 1 \cos 4+\cos 1 \sin 4)$, where $1$ and $4$ appearing in sin and cos are given in radians, is

If $ a $ has magnitude $5$ and points north-east and vector $b $ has magnitude $ 5$ and points north-west, then $|\,\,a - b\,\,|\, = $

$\int_{}^{} {{{\sin }^3}x\;dx} $ is equal to