Question
Question: If the matrix A= \(\begin{bmatrix} 8 & - 6 & 2 \\ - 6 & 7 & - 4 \\ 2 & - 4 & \lambda \end{bmatrix}\...
If the matrix A= $\begin{bmatrix} 8 & - 6 & 2 \
- 6 & 7 & - 4 \
2 & - 4 & \lambda
\end{bmatrix}$is singular, then
=
A
3
B
4
C
2
D
5
Answer
3
Explanation
Solution
If matrix A is singular. Then |A| =0
8 & - 6 & 2 \\ - 6 & 7 & - 4 \\ 2 & - 4 & \lambda \end{matrix} \right| = 0$$ ⇒ $8(7\lambda - 16) + 6( - 6\lambda + 8) + 2(24 - 14) = 0$ ⇒ $\lambda = 3$