Download App

Determinants — Maths STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceMathsDeterminants1 Mark
MCQ
If $\left|\begin{array}{ll}3 & 3 \\ x & 1\end{array}\right|=\left|\begin{array}{cc}-3 & x \\ 1 & 1\end{array}\right|$ then value of $x$ is :
  • A
    2
  • ✓
    3
  • C
    -3
  • D
    -2
✓

Answer

Correct option: B.
3
(B)$\quad\left|\begin{array}{ll}3 & 3 \\ x & 1\end{array}\right|=\left|\begin{array}{cc}-3 & x \\ 1 & 1\end{array}\right|$
$
\begin{aligned}
\Rightarrow & & 3-3 x & =-3-x \\
\Rightarrow & & 3+3 & =3 x-x \\
\Rightarrow & & 6 & =2 x \Rightarrow x=3
\end{aligned}
$

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 projection of $\vec{\text{a}}=\hat{\text{i}}-2\hat{\text{j}}+3\hat{\text{k}}$ on $\vec{\text{b}}=2\hat{\text{i}}+\lambda\hat{\text{k}}$ is zero, then the value of $\lambda$ is :
→
If $\int {}  e^{3x}\, \cos\, 4x \,dx\, = \, e^{3x}\,$ $(A \sin \,4x + B\, \cos \,4x)$ $+ c$ then :
→
Consider a $\triangle \mathrm{ABC}$ where $\mathrm{A}(1,3,2), \mathrm{B}(-2,8,0)$ and $\mathrm{C}(3,6,7)$. If the angle bisector of $\angle \mathrm{BAC}$ meets the line $B C$ at $D$, then the length of the projection of the vector $\overrightarrow{A D}$ on the vector $\overrightarrow{A C}$ is:
→
$\int_{-\pi / 4}^{\pi / 4} \sec ^2 x d x$ is equal to
→
If $\text{A}=\begin{bmatrix}3&\text{x}-1\\2\text{x}+3&\text{x}+2\end{bmatrix}$ is a symmetric matrix, then $x =$
→
If $A$ satisfies the equation $\text{x}^2-5\text{x}^2+4\text{x}+\lambda=0$ then $A^{-1}$ exists if :
→
Let $f(x)$ be a differentiable function which satisfies the equation $f(xy) = f(x) + f(y)$ for all $x > 0, y > 0$ then $f ‘(x)$ is equal to
→
$\mathop {{\rm{lim}}\,}\limits_{n \to \infty } \left[ {\frac{1}{{{n^2}}}{{\sec }^2}\frac{1}{{{n^2}}} + \frac{2}{{{n^2}}}{{\sec }^2}\frac{4}{{{n^2}}} + ..... + \frac{1}{n}{{\sec }^2}1} \right]$ equals
 
→
ox, oy are positive x-axis, positive y-axis respectively where O = (0, 0,0) The d.c.s of the llne which bisects $\angle\text{xoy}$ are:
→
Let $A_1, A_2, A_3$ be regions in the $X Y$-plane defined by

$A_1=\left\{(x, y): x^2+2 y^2 \leq 1\right\}$

$A_2=\left\{(x, y):\left|x^3\right|+2 \sqrt{2} \mid y^3 \leq 1\right\}$

$A_3=\{(x, y): \max (|x|, \sqrt{2}|y|) \leq 1\}$ Then,

→