MCQ
If $A = \left[ {\begin{array}{*{20}{c}}4&{x + 2}\\{2x - 3}&{x + 1}\end{array}} \right]$is symmetric, then $ x =$
  • A
    $3$
  • $5$
  • C
    $2$
  • D
    $4$

Answer

Correct option: B.
$5$
b
(b) Since the given matrix is symmetric, therefore

${a_{12}} = {a_{21}} \Rightarrow x + 2 = 2x - 3 \Rightarrow x = 5$.

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

Solution of the following $LP$ problem

Minimize $z=-3 x+2 y$

subject to $0 \leq x \leq 4,1 \leq y \leq 6, x+y \leq 5$ is $.....$

If $\left[ {\begin{array}{*{20}{c}}x&0\\1&y\end{array}} \right] + \left[ {\begin{array}{*{20}{c}}{ - 2}&1\\3&4\end{array}} \right] = \left[ {\begin{array}{*{20}{c}}3&5\\6&3\end{array}} \right] - \left[ {\begin{array}{*{20}{c}}2&4\\2&1\end{array}} \right]$, then
If the fucnction $\text{f(x)}=\begin{cases}(\cos\text{x})^{\frac{1}{\text{x}}},&\text{x}\neq0\\\text{k},&\text{x}=0\end{cases}$ is continuouse at x = 0, then the value of k is:
The corner points of the feasible region determined by the system of linear constraints are (0, 10), (5, 5), (15, 15), (0, 20). Let z = px + qy where p, q > 0. Condition on p and q so that the maximum of z occurs at both the points (15, 15) and (0, 20) is __________.
Choose the correct answer from the given four options.
If $\text{P}(\text{A})=\frac{3}{10},\text{P}(\text{B})=\frac{2}{5}$ and $\text{P}(\text{A}\cup\text{B})=\frac{3}{5},$ then $\text{P}\Big(\frac{\text{B}}{\text{A}}\Big)+\text{P}\Big(\frac{\text{A}}{\text{B}}\Big)$ equas:
Let $f (x) = a^x (a > 0)$ be written as $f( x) = f_1( x) + f_2( x)$ , where $f_1( x)$ is an even function and $f_2( x)$ is an odd function. Then $f_1( x + y) + f_1( x - y )$ equals
The period of the function $f(x) = \log \cos 2x + \sin 4x$ is :-
Let $f:R \to R$ be a function. Define $g:R \to R$ by $g(x) = \,|f(x)|$ for all $x$. Then $g$ is
If $f : R \rightarrow R$ is given by $f(x) = 3x - 5,$ then $f^{-1}(x)$
A bag contains $5$ brown and $4$ white socks. A man pulls out two socks. The probability that these are of the sane colour is.