MCQ
Matrix $A = \left[ {\begin{array}{*{20}{c}}1&0&{ - k}\\2&1&3\\k&0&1\end{array}} \right]$ is invertible for
  • A
    $k = 1$
  • B
    $k = - 1$
  • C
    $k = 0$
  • All real $k$

Answer

Correct option: D.
All real $k$
d
(d) On expansion, $|A| = {k^2} + 1$, which can be never zero.

.Hence matrix $A$ is invertible for all real $k.$

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