alleryIf A is 3×3 and det(A) = 5, then det(A⁻¹) equals:
A5
B1/5
C0
D-5
Answer & Solution
Correct answer: B. 1/5
det(A⁻¹) = 1/det(A) = 1/5. Property: det(AB) = det(A)·det(B).
Apply to AA⁻¹ = I: det(A)·det(A⁻¹) = det(I) = 1.
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