Determinant Practice Questions Ques5
Question: If $A$ is a $3 \times 3$ matrix, what is the minor of the element $a_{31}$?
Options:
(A) The determinant of the $2 \times 2$ matrix obtained by deleting the third row and second column of $A$
(B) The determinant of the $2 \times 2$ matrix obtained by deleting the first row and third column of $A$
(C) The determinant of the $2 \times 2$ matrix obtained by deleting the second row and first column of $A$
(D) The determinant of the $2 \times 2$ matrix obtained by deleting the third row and first column of $A$
Show Answer
Answer: D
Explanation:
(A) Incorrect. This would be the minor of $a_{32}$.
(B) Incorrect. This would be the minor of $a_{13}$.
(C) Incorrect. This would be the minor of $a_{21}$.
(D) Correct. The minor of $a_{31}$ is the determinant of the $2 \times 2$ matrix obtained by deleting the third row and first column of $A$.
BETA
