If $A=\begin{bmatrix}5&2\\4&3\end{bmatrix}$ is a given matrix, then which of the following statements are correct? (A) $|A|=7$ Choose the correct answer from the options given below. |
(A), (C) and (D) only (A), (B) and (C) only (B), (C) and (D) only (A), (B) and (D) only |
(A), (C) and (D) only |
The correct answer is Option (1) → (A), (C) and (D) only ** $A=\begin{bmatrix}5&2\\4&3\end{bmatrix}$ (A) $|A|=5\cdot3-2\cdot4=15-8=7$ → True (B) Minor of element $3$ is the determinant of the submatrix left after removing its row & column → minor = $5$ (not $-5$) → False (C) Cofactor of $2$: Minor of $2$ = $4$ Position of $2$ is $(1,2)$ → sign $=(-1)^{1+2}=-1$ Cofactor = $-4$ → True (D) $\text{adj}(A)=\begin{bmatrix}3&-2\\-4&5\end{bmatrix}$ → True Correct statements: (A), (C), (D) |