If $\left| {\begin{array}{*{20}{c}} {b + c}&{c + a}&{a + b}\\ {a + b}&{b + c}&{c + a}\\ {c + a}&{a + b}&{b + c} \end{array}} \right| = k\left| {\begin{array}{*{20}{c}} a&b&c\\ c&a&b\\ d&c&a \end{array}} \right|,$ then the value of $k$, is

JEE MATHEMATICS MCQ: MATRICES

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\left| {\begin{array}{cccccccccccccccccccc} {b + c}&{c + a}&{a + b}\\ {a + b}&{b + c}&{c + a}\\ {c + a}&{a + b}&{b + c} \end{array}} \right| = k\left| {\begin{array}{cccccccccccccccccccc} a&b&c\\ c&a&b\\ d&c&a \end{array}} \right|,

then the value of

k

, is

View answer and explanation

Correct option: B

Option B (2) is correct because by applying column operations to the left-hand side determinant, it simplifies to 2 times the determinant on the right-hand side, thus k=2.

More Questions from MATRICES

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\left|\begin{array}{ccc}a & b-c & b+c \\ c+a & b & c-a \\ a-b & a+b & c\end{array}\right|=0

and

a, b, c

are real numbers then the line

a x+b y+c=0

passes through the fixed point is The number of solutions of the system of equations

{x_2} - {x_3} = 1,\; - {x_1} + 2{x_3} = - 2,\;{x_1} - 2,\;{x_1} - 2{x_2} = 3

is If the equations

2x + 3y + 1 = 0,3x + y - 2 = 0

and

ax + 2y - b = 0

are consistent, then The value of the determinant

\left|\begin{array}{ccc}1 & \left(\alpha^{2 x}-\alpha^{-2 x}\right)^2 & \left(\alpha^{2 x}+\alpha^{-2 x}\right)^2 \\ 1 & \left(\beta^{2 x}-\beta^{-2 x}\right)^2 & \left(\beta^{2 x}+\beta^{-2 x}\right)^2 \\ 1 & \left(\gamma^{2 x}-\gamma^{-2 x}\right)^2 & \left(\gamma^{2 x}+\gamma^{-2 x}\right)^2\end{array}\right|

, is If

\omega

is the cube root of unity, then

\left| {\begin{array}{cccccccccccccccccccc} 1&\omega &{{\omega ^2}}\\ \omega &{{\omega ^2}}&1\\ {{\omega ^2}}&1&\omega \end{array}} \right|

is equal to For any matrix

A

of order

2 \times 2

, if

A(\operatorname{adj} A)=\left[\begin{array}{cc}10 & 0 \\ 0 & 10\end{array}\right]

, then

|A|

is equal to