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CUET · MATHS · PYQ PAPER 2023

If \(A=\left[\begin{array}{lll}1 & 1 & -2 \\ 2 & 1 & -3 \\ 5 & 4 & -9\end{array}\right]\), then \(|A|\) is equal to:

  1. A \(0\)
  2. B 1
  3. C -1
  4. D 2
Verified Solution

Answer & Solution

Correct Answer

(A) \(0\)

Step-by-step Solution

Detailed explanation

\(|A| = 1((1)(-9) - (-3)(4)) - 1((2)(-9) - (-3)(5)) + (-2)((2)(4) - (1)(5))\) \(|A| = 1(-9 + 12) - 1(-18 + 15) - 2(8 - 5)\) \(|A| = 1(3) - 1(-3) - 2(3)\) \(|A| = 3 + 3 - 6\) \(|A| = 0\)