2. Sample Papers
  3. JEE Main & Advanced

JEE Main & Advanced Sample Paper JEE Main Sample Paper-44

  • question_answer
    Let A be a matrix of order \[3\times 3\] and matrices B,C and D are related such that \[B=adj\,(A),\]\[C=adj\,(adj\,A),\]\[D=(adj\,(adj(adj\,A)))\] if \[|adj\,(adj\,(adj\,(adj\,ABCD)))|\] is \[|A{{|}^{k}}\], then k

    A)  is independent of a           

    B)  is independent of b

    C)  is independent of a and b              

    D)  depends on both a and b

    Correct Answer: A

    Solution :

              Let \[ABCD=E\] \[|adj\,(adj\,(adj\,(adj\,E)))|\] \[=|E{{|}^{{{(3-1)}^{4}}}}=\,|E{{|}^{16}}=\,|ABCD{{|}^{16}}\] \[=\,|A{{|}^{16}}|B{{|}^{16}}|C{{|}^{16}}|D{{|}^{16}}\] \[=\,|A{{|}^{16+32+64+128}}\] \[|A{{|}^{k}}=\,|A{{|}^{240}}\] \[\Rightarrow \]            \[k=240\]


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