MCQ
If $\left|\begin{array}{ll}2 & 4 \\ 5 & 1\end{array}\right|=\left|\begin{array}{cc}2 x & 4 \\ 6 & x\end{array}\right|$, then the possible value(s) of ' $x$ ' is/are
  • A
    3
  • B
    $\sqrt{3}$
  • C
    $-\sqrt{3}$
  • D
    $\sqrt{3},-\sqrt{3}$

Answer

We have, $\left|\begin{array}{ll}2 & 4 \\ 5 & 1\end{array}\right|=\left|\begin{array}{cc}2 x & 4 \\ 6 & x\end{array}\right|$
$\Rightarrow \quad 2-20=2 x^2-24 \Rightarrow 2 x^2=6 \Rightarrow x^2=3 \Rightarrow x= \pm \sqrt{3}$

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

Similar questions

Find the area above $x$-axis, bounded by the curves $y=2^{k x}, x=0$ and $x=2$.
Direction cosines of ray from P(1, −2, 4) to Q(−1, 1, −2) are:
If $d$ is the determinant of a square matrix $A$ of order $n,$ then the determinant of its adjoint is:
$\int_0^{\pi /4} {\frac{{\sec x}}{{1 + 2{{\sin }^2}x}}} $ is equal to
The probabilities of a student getting I, II and III division in an examination are $\frac{1}{10},\frac{3}{5}$ and $\frac{1}{4}$ respectively. The probability that the student fails in the examination is.
The function ${x^x}$ is increasing, when
Let $P = \{ (x,\,y)|{x^2} + {y^2} = 1,\,x,\,y \in R\} $. Then $P$ is
Choose the correct answer from the given four options.
The vectors from origin to the points A and B are $\vec{\text{a}}=2\hat{\text{i}}-3\hat{\text{j}}+2\hat{\text{k}}$ and $\vec{\text{b}}=2\hat{\text{i}}+3\hat{\text{j}}+\hat{\text{k}},$ respectively, then the area of the triangle OAB is:
If a binary operation $^*$ is defined on the set $Z$ of integers as $a ^* b = 3a − b,$ then the value of $(2 ^* 3) ^* 4$ is:
If the polynomial equation $\text{a}_0\text{x}^{\text{n}}+\text{a}_{\text{n}-1}\text{x}^{\text{n}-1}+\text{a}_{\text{n}-2}\text{x}^{\text{n}-2}+...\text{a}_2\text{x}^2+\text{a}_1\text{x}+\text{a}_0=0$ n positive integer,has two different real roots $\alpha$ and $\beta,$ then between $\alpha$ and $\beta,$ the equation $\text{n}\text{a}_{\text{n}}\text{x}^{\text{n}-1}+(\text{n}-1)\text{a}_{\text{n}-1}\text{x}^{\text{n}-2}+...+\text{a}_1=0$ has: