Question
Question: If A is a 3 × 3 skew-symmetric matrix, then \|A\| is given by –...
If A is a 3 × 3 skew-symmetric matrix, then |A| is given by –
A
0
B
–1
C
1
D
None of these
Answer
0
Explanation
Solution
Let A = $\begin{pmatrix} 0 & a & b \
- a & 0 & c \
- b & - c & 0 \end{pmatrix}bethegivenskewsymmetricmatrix.Wehave∥A∥=\begin{pmatrix} 0 & a & b \
- a & 0 & c \
- b & - c & 0 \end{pmatrix}=\left| \begin{matrix} 0 & - a & - b \ a & 0 & - c \ b & c & 0 \end{matrix} \right|$
[Q |A| = |A¢|] = (–1)3 $\left| \begin{matrix} 0 & a & b \
- a & 0 & c \
- b & - c & 0 \end{matrix} \right|$ = – |A|
Ž 2 |A| = 0 Ž |A| = 0.