JEE Main & Advanced Sample Paper JEE Main Sample Paper-40

  • question_answer
    Matrix \[{{M}_{r}}\] is defined as  value of det \[({{M}_{1}})+\det ({{M}_{2}})+\det ({{M}_{3}})+....+\det ({{M}_{2007}})\] is

    A) 2007                           

    B) 2008

    C) 20082                          

    D) 20072

    Correct Answer: D

    Solution :

    det\[({{M}_{r}})=\left| \begin{matrix}    r & r-1  \\    r-1 & r  \\ \end{matrix} \right|=2r-1\] \[\sum\limits_{r=l}^{2007}{\det }({{M}_{r}})=2\sum\limits_{r=l}^{2007}{r-2007}\] \[=2\times \frac{2007\times 2008}{2}-2007={{(2007)}^{2}}\]


You need to login to perform this action.
You will be redirected in 3 sec spinner