If the matrix ${M_r}$ is given by ${M_r} = \left[ {\begin{array}{*{20}{c}} r&{r - 1}\\ {r - 1}&r \end{array}} \right]r = 1,2,3...,$ then the value of det $\left( {{M_1}} \right) + \det \left( {{M_2}} \right) + ... + \det ({M_{2008}})$ is

JEE MATHEMATICS MCQ: MATRICES

1 Easy

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Application +4 | -1

If the matrix

{M_r}

is given by

{M_r} = \left[ {\begin{array}{cccccccccccccccccccc} r&{r - 1}\\ {r - 1}&r \end{array}} \right]r = 1,2,3...,

then the value of det

\left( {{M_1}} \right) + \det \left( {{M_2}} \right) + ... + \det ({M_{2008}})

View answer and explanation

Correct option: C

{\left( {2008} \right)^2}

Option C (

(2008)^2

) is correct because the determinant of

M_r

simplifies to

2r - 1

, and the sum of the first 2008 odd numbers is

(2008)^2

Practice All Chapter MCQs →

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

a, b, c

a x+b y+c=0

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

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

ax + 2y - b = 0

\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|

\omega

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

A

2 \times 2

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

|A|