Q46 / 160 · TS EAMCET 2020 (10 Sep Shift 2) · Mathematics

If $C$ and $D$ are two $n \times n$ non-singular matrices over the set of real number $\mathbf{R}$ such that $C D=-D C$, then $n$ is

  • A
    a natural number of the form $3 k+5, k \in N$
  • B
    an odd integer
  • Correct answer
    C
    $n$ even integer
  • D
    equal to one

Solution

Given, $C$ and $D$ are non-singular matrix of order $n$ $\because \quad|C| \neq 0,|D| \neq 0$ $C D=-D C$ $|C D|=|-D C|$ $|C||D|=(-1)^n|D||C|$ $\mathrm{l}=(-1)^n$ $\therefore n$ is even integer.

Hence, the correct answer is option: 'C'.

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