Cofactor

Q. For any 4 x 4 matrix A, if adjA. adj(adjA)0 8 0 0then \vert Al isIS0 0 0 8(2) 8(3) 2(4) 8

Q. The cofactor of the element '4' in the determinant $\left|\begin{array}{cccc}1& 3& 5& 1\\ 2& 3& 4& 2\\ 8& 0& 1& 1\\ 0& 2& 1& 1\end{array}\right|$ is

1. 4
2. -10
3. 10
4. -4

Q. The cofactor of element '5' in the matrix $\left(\begin{array}{ccc}1& -3& 2\\ 4& -1& 2\\ 3& 5& 2\end{array}\right]$ will be .

1. -12
2. 14
3. 6
4. -30

Q.

If A1, B1, C1 … are the cofactors of the elements a1, b1, c1... of the matrix

$\left[\begin{array}{ccc}a1& b1& c1\\ a2& b2& c2\\ a3& b3& c3\end{array}\right]$ then $\left|\begin{array}{cc}B2& C2\\ B3& C3\end{array}\right|=$

1. a1 D

2. a1a3D

3. (a1 +a2)D

4. None of these