If $\begin{bmatrix}x-1 & y-2 & z-3\\3 & u-4 & v-5\\8 & -4 & w-6\end{bmatrix}$ is skew symmetric matrix, then xu + yv + zw is:
Answer & explanation
Correct answer: option 4
For skew - symmetric matrix diagonal element must be zero
∴ x = 1, u = 4, w = 6
and non diagonal element must be of opposite sign.
∴ y - 2 = -3, z - 3 = -8, v - 5 = 4
∴ y = -1, z = -5, v = 9
xu + yv + zw = (1)(4) + (-1)(9) + (-5)(6)
= 4 - 9 - 30 = -35