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COMEDK20269 May 2026Evening ShiftMathematicsDeterminantsActual

Let A be a square matrix of order 3 3 . If |A| = -4 , then the value of | A⁻¹ -2 | is:

Options

  1. A-1
  2. B- 1 16
  3. C1 32
  4. D2

Correct answer

C. 1 32

Step-by-step solution

Given A is a 3 3 matrix and |A| = -4 . Using the property of determinants |kA| = k^n |A| where n is the order of the matrix, we get: | A⁻¹ -2 | = |- 1 2 A⁻¹ | = (- 1 2 )^3 |A⁻¹| Since |A⁻¹| = 1 |A| : Substituting |A| = -4 , we get |A⁻¹| = - 1 4 . Therefore, | A⁻¹ -2 | = (- 1 8 ) (- 1 4 ) = 1 32 . Answer: 1 32

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