Answer
$(-2,-2,-1)$
Work Step by Step
We know that for a matrix
$
\left[\begin{array}{rrr}
a & b & c \\
d &e & f \\
g &h & i \\
\end{array} \right]
$
the determinant, $D=a(ei-fh)-b(di-fg)+c(dh-eg).$
$u\times v$ is the determinant of the matrix $\begin{bmatrix}
i & j& k \\
0&1&-2\\
1&-1&0\\
\end{bmatrix}
$
Thus $u\times v=(-2,-2,-1)$
$(-2,-2,-1)(0,1,-2)=0-2+2=0$, $(-2,-2,-1)(1,-1,0)=-2+2-0=0$,
thus it is orthogonal to both $u$ and $v$.
