If matrix $A =\begin{bmatrix}x&2&3\\a&y&-5\\b&c&0\end{bmatrix}$ is a skew-symmetric matrix, then (A) $x+y+c =5$ Choose the correct answer from the options given below: |
(A) and (B) only (A), (B) and (C) only (D) and (A) only (A) and (C) only |
(A), (B) and (C) only |
The correct answer is Option (2) → (A), (B) and (C) only Given matrix: $A = \begin{bmatrix} x & 2 & 3 \\ a & y & -5 \\ b & c & 0 \end{bmatrix}$ Property of skew-symmetric matrix: $A^T = -A$, so diagonal elements = 0 Therefore, $x = 0$, $y = 0$, and $0$ (already) for third diagonal Off-diagonal elements satisfy: $a_{ij} = -a_{ji}$ Check (2,1) element: $a = -2 \Rightarrow a = -2$ Check (3,1) element: $b = -3 \Rightarrow b = -3$ Check (3,2) element: $c = 5 \Rightarrow c = 5$ Now evaluate options: (A) x+y+c = 0+0+5 = 5 ✅ (B) c = 5 ✅ (C) a+b+c = -2 + (-3) + 5 = 0 ✅ (D) a+b−c = -2 + (-3) − 5 = -10 ❌ |