MathCastle
Linear AlgebraHardDeterminants & Inverses

Determinants & Inverses · Hard problem

For any invertible n×nn\times n matrix AA, the adjugate satisfies A⋅adj⁡(A)=(det⁡A) InA\cdot\operatorname{adj}(A) = (\det A)\,I_n. A 4×44\times4 matrix AA has det⁡A=3\det A = 3. Find det⁡(adj⁡(A))\det(\operatorname{adj}(A)).