Cofactor

Q.

Cofactor of 4 in the determinant $\left|\begin{array}{ccc}1& 2& -3\\ 4& 5& 0\\ 2& 0& 1\end{array}\right|$ is equal to

___ .

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 minors of - 4 and 9 and the co-factors of - 4 and 9 in determinant $\left|\begin{array}{ccc}-1& -2& 3\\ -4& -5& -6\\ -7& 8& 9\end{array}\right|$ are respectively

1. 42, 3 ; – 42, 3

2. –42, –3 ; 42, –3

3. 42, 3 ; – 42, – 3

4. 42, 3; 42, 3

Q. If A = $\left|\begin{array}{ccc}5& 6& 3\\ -4& 3& 2\\ -4& -7& 3\end{array}\right|,$ then cofactors of the elements of $2^{nd}$ row are

1. 39, -3, 11
2. -39, 3, 11
3. -39, 27, 11
4. -39, -3, 11