RAJASTHAN ­ PET Rajasthan PET Solved Paper-2001

  • question_answer
    If\[{{a}_{ij}}=\frac{1}{2}2i-3j,\]then matrix\[{{A}_{2\times 2}}=[{{a}_{ij}}]\]is equal to

    A)  \[\left[ \begin{matrix}    1/2 & 2  \\    1/2 & 1  \\ \end{matrix} \right]\]

    B)  \[\left[ \begin{matrix}    2 & 2  \\    1/2 & 1/2  \\ \end{matrix} \right]\]

    C)  \[\left[ \begin{matrix}    1/2 & -2  \\    -1/2 & 1  \\ \end{matrix} \right]\]

    D)  None of these

    Correct Answer: C

    Solution :

     \[{{A}_{2\times 2}}=[{{a}_{ij}}]=\left[ \begin{matrix}    {{a}_{11}} & {{a}_{12}}  \\    {{a}_{21}} & {{a}_{22}}  \\ \end{matrix} \right]\] \[{{a}_{ij}}=\frac{1}{2}|2i-3j|\] \[\therefore \] \[{{a}_{11}}=\frac{1}{2}|2-3|=\frac{1}{2}\] \[{{a}_{12}}=\frac{1}{2}|2-6|=2\] \[{{a}_{21}}=-\frac{1}{2}|4-3|=\frac{1}{2}\] \[{{a}_{22}}=\frac{1}{2}|4-6|=1\] \[{{A}_{2\times 2}}=\left[ \begin{matrix}    \frac{1}{2} & 2  \\    \frac{1}{2} & 1  \\ \end{matrix} \right]\]


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