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If A=[1−320]A = \begin{bmatrix} 1 & -3 \\ 2 & 0 \end{bmatrix}, then which of the following statement(s) is/are TRUE?

(A) Matrix A is non-singular

(B) ∣3A∣=54|3A| = 54

(C) ∣adjA∣=36|adjA| = 36

(D) A2=[−5−32−6]A^2 = \begin{bmatrix} -5 & -3 \\ 2 & -6 \end{bmatrix}

Choose the correct answer from the options given below:

Solution

✅ Correct Option: 2

∣A∣=6≠0|A| = 6 \ne 0, so A is non-singular: (A) true. ∣3A∣=32∣A∣=54|3A| = 3^2|A| = 54: (B) true. ∣adjA∣=∣A∣2−1=6|\text{adj}A| = |A|^{2-1} = 6, not 36, so (C) is false. Direct multiplication gives A2=[−5−32−6]A^2 = \begin{bmatrix} -5 & -3 \\ 2 & -6 \end{bmatrix}: (D) true.

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