MCQ
If $A = \left( {\begin{array}{*{20}{c}}1&2&0\\0&1&2\\2&0&1\end{array}} \right),$then $adj \,A$
  • A
    $\left( {\begin{array}{*{20}{c}}1&4&{ - 2}\\{ - 2}&1&4\\4&{ - 2}&1\end{array}} \right)$
  • $\left( {\begin{array}{*{20}{c}}1&{ - 2}&4\\4&1&{ - 2}\\{ - 2}&4&1\end{array}} \right)$
  • C
    $\left( {\begin{array}{*{20}{c}}1&2&4\\{ - 4}&1&2\\{ - 4}&{ - 2}&1\end{array}} \right)$
  • D
    None of these

Answer

Correct option: B.
$\left( {\begin{array}{*{20}{c}}1&{ - 2}&4\\4&1&{ - 2}\\{ - 2}&4&1\end{array}} \right)$
b
(b) $A = \left[ {\begin{array}{*{20}{c}}1&2&0\\0&1&2\\2&0&1\end{array}} \right]$,

${A_{11}} = 1,\,{A_{21}} = - 2,\,{A_{31}} = 4$

${A_{12}} = 4,\,{A_{22}} = 1,\,{A_{32}} = - 2$

${A_{13}} = - 2,\,{A_{23}} = 4,\,{A_{33}} = 1$

$Adj\,(A) = \left[ {\begin{array}{*{20}{c}}1&{ - 2}&4\\4&1&{ - 2}\\{ - 2}&4&1\end{array}} \right]$.

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

A tangent line $\mathrm{L}$ is drawn at the point $(2,-4)$ on the parabola $\mathrm{y}^{2}=8 \mathrm{x}$. If the line $\mathrm{L}$ is also tangent to the circle $x^{2}+y^{2}=a$, then $'a'$ is equal to .... .
If $a = - 3i + 7j + 5k,$ $b = - 3i + 7j - 3k$, $c = 7i - 5j - 3k$ are the three coterminous edges of a parallelopiped, then its volume is
Let ${z_1}$ and ${z_2}$ be two complex numbers such that $\frac{{{z_1}}}{{{z_2}}} + \frac{{{z_2}}}{{{z_1}}} = 1$. Then
If the roots of the equation $\frac{\alpha }{{x - \alpha }} + \frac{\beta }{{x - \beta }} = 1$ be equal in magnitude but opposite in sign, then $\alpha + \beta $=
If $f(x) = {1 \over {\sqrt {{x^2} + {a^2}} + \sqrt {{x^2} + {b^2}} }}$, then $f'(x)$ is equal to
If ${\Delta _1} = \left| {\begin{array}{*{20}{c}}
  {{b^5}{c^6}\left( {{c^3} - {b^3}} \right)}&{{a^4}{c^6}\left( {{a^3} - {c^3}} \right)}&{{a^4}{b^5}\left( {{b^3} - {a^3}} \right)} \\ 
  {{b^2}{c^3}\left( {{b^6} - {c^6}} \right)}&{a{c^3}\left( {{c^6} - {a^6}} \right)}&{a{b^2}\left( {{a^6} - {b^6}} \right)} \\ 
  {{b^2}{c^3}\left( {{c^3} - {b^3}} \right)}&{a{c^3}\left( {{a^3} - {c^3}} \right)}&{a{b^2}\left( {{b^3} - {a^3}} \right)} 
\end{array}} \right|$ and ${\Delta _2} = \left| {\begin{array}{*{20}{c}}
  a&{{b^2}}&{{c^3}} \\ 
  {{a^4}}&{{b^5}}&{{c^6}} \\ 
  {{a^7}}&{{b^8}}&{{c^9}} 
\end{array}} \right|$ then ${\Delta _1}{\Delta _2}$ is equal to
The orthocentre of triangle formed by lines $4x - 7y + 10 = 0,$ $x + y = 5$ and $7x + 4y = 15$ is
A tangent is drawn to the ellipse $\frac{{{x^2}}}{{32}} + \frac{{{y^2}}}{8} = 1$ from the point $A(8, 0)$ to touch the ellipse at point $P.$ If the normal at $P$ meets the major axis of ellipse at point $B,$ then the length $BC$ is equal to (where $C$ is centre of ellipse) - ............ $\mathrm{units}$
The locus of the mid points of the chords of the circle $x^2 + y^2 + 4x - 6y - 12 = 0$ which subtend an angle of $\frac{\pi }{3}$ radians at its circumference is :
If for positive integers $r> 1, n > 2$, the coefficients of the $(3r)^{th}$ and $(r + 2)^{th}$ powers of $x$ in the expansion of $( 1 + x)^{2n}$ are equal, then $n$ is equal to