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

If the shortest distance between the lines $\frac{x+2}{2}=\frac{y+3}{3}=\frac{z-5}{4}$ and $\frac{x-3}{1}=\frac{y-2}{-3}=\frac{z+4}{2}$ is $\frac{38}{3 \sqrt{5}} \mathrm{k}$ and $\int_0^{\mathrm{k}}\left[\mathrm{x}^2\right] \mathrm{dx}=\alpha-\sqrt{\alpha}$, where $[\mathrm{x}]$ denotes the greatest integer function, then $6 \alpha^3$ is equal to ............................
→
The slope of a curve at any point is the reciprocal of twice the ordinate at the point and it passes though the point $(4, 3)$. The equation of the curve is
→
Let $f : R \rightarrow R$ be a differentiable function such that $f (2) = 2$. Then the value of $\mathop {Limit}\limits_{x\,\, \to \,\,2}\, \int\limits_2^{f\,(x)} {\,\,\frac{{4\,{t^3}}}{{x\, - \,2}}}\,dt$ is
→
The value of $\int_3^5 {\frac{{{x^2}}}{{{x^2} - 4}}\,dx} $ is
→
Let $|\vec{a}|=2,|\vec{b}|=3$ and the angle between the vectors $\vec{a}$ and $\vec{b}$ be $\frac{\pi}{4}$. Then $|(\vec{a}+2 \vec{b}) \times(2 \vec{a}-3 \vec{b})|^2$ is equal to
→
The area (in sq. units) of the region described by $\left\{(\mathrm{x}, \mathrm{y}): \mathrm{y}^2 \leq 2 \mathrm{x}\right.$, and $\left.\mathrm{y} \geq 4 \mathrm{x}-1\right\}$ is
→
The value of $\int_{-2}^{2}\left|3 x^{2}-3 x-6\right| d x$ is ...... .
→
Let $f :\left[\frac{1}{2}, 1\right] \rightarrow R$ (the set of all real numbers) be a positive, non-constant and differentiable function such that $f^{\prime}(x)<2 f(x)$ and $f\left(\frac{1}{2}\right)=1$. Then the value of $\int_{1 / 2}^1 f(x) d x$ lies in the interval
→
Choose the correct answer from the given four options.

If two events are independent, then:

→
$\int_{ - \pi }^\pi {{{(\cos px - \sin qx)}^2}dx} $ is equal to (where $p$ and $q$ are integers)
→