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CUET · MATHS · PYQ PAPER 2023

Which of the following matrices is not invertible?

  1. A \(\left[\begin{array}{ll}1 & 1 \\ 0 & 1\end{array}\right]\)
  2. B \(\left[\begin{array}{ll}2 & 3 \\ 4 & 6\end{array}\right]\)
  3. C \(\left[\begin{array}{cc}-1 & -1 \\ -1 & 5\end{array}\right]\)
  4. D \(\left[\begin{array}{cc}2 & -2 \\ 1 & 1\end{array}\right]\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(\left[\begin{array}{ll}2 & 3 \\ 4 & 6\end{array}\right]\)

Step-by-step Solution

Detailed explanation

\( \det \left( \left[ \begin{array}{ll} 2 & 3 \\ 4 & 6 \end{array} \right] \right) = (2)(6) - (3)(4) \) \( = 12 - 12 \) \( = 0 \) \(\left[ \begin{array}{ll} 2 & 3 \\ 4 & 6 \end{array} \right]\)