Download App

Determinants — Maths STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceMathsDeterminants1 Mark
MCQ
Find the values of $x$ for which $\left|\begin{array}{ll}3 & x \\ x & 1\end{array}\right|=\left|\begin{array}{ll}3 & 2 \\ 4 & 1\end{array}\right|$.
  • A
    $2 \sqrt{2}$
  • B
    $-2 \sqrt{2}$
  • C
    3
  • ✓
    both (a) and (b)
✓

Answer

Correct option: D.
both (a) and (b)
(d) : We have, $\left|\begin{array}{ll}3 & x \\ x & 1\end{array}\right|=\left|\begin{array}{ll}3 & 2 \\ 4 & 1\end{array}\right|$
$
\Rightarrow \quad 3-x^2=3-8 \quad \Rightarrow \quad x^2=8 \text {. Hence, } x= \pm 2 \sqrt{2}
$

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 Determinants→Determinants — all question types→Maths STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

Which of the following functions from $\text{A}=\{\text{x}\in\text{R}:-1\leq\text{x}\leq1\}$ to itself are bijections?
→
$\int_0^{1/\sqrt 2 } {\frac{{{{\sin }^{ - 1}}x}}{{{{(1 - {x^2})}^{3/2}}}}dx = } $
→
Choose the correct answer from the given four options:
The maximum value of $\sin\text{x}\cdot\cos\text{x}$ is:
→
A ladder  $5\ m$ in length is resting against vertical wall. The bottom of the ladder is pulled along the ground away from the wall at the rate of $1.5\,m/\sec $. The length of the highest point of the ladder when the foot of the ladder $4.0\,m$ away from the wall decreases at the rate of .......... $m/sec$
→
Area bounded by the lines $y = |x| - 2$ and $y = 1 - |x - 1|$ is equal to:
→
If $A$ is a square matrix, then $A-A^{\prime}$ is a
→
Using the factor theorem it is found that a + b, b + c and c + a are three factors of the determinant $\begin{vmatrix}-2\text{a}&\text{a}+\text{b}&\text{a}+\text{c}\\\text{b}+\text{a}&-2\text{b}&\text{b}+\text{c}\\\text{c}+\text{a}&\text{c}+\text{b}&-2\text{c}\end{vmatrix}$ the other factor in the value of the determinant is:
→
$\int\text{e}^{\text{x}}\{\text{f(x)}+\text{f}'(\text{x})\}\text{dx}=$
→
The value of $b>3$ for which

$12 \int \limits_{3}^{b} \frac{1}{\left(x^{2}-1\right)\left(x^{2}-4\right)} d x=\log _{e}\left(\frac{49}{40}\right)$, is equal to

→
The area of the region between the curve $y^2=4 a x$, line $y=2 a$ and $y$-axis is :
→