Answer
The two vectors u and v can be perpendicular when $t=2; -1$
Work Step by Step
We know that the two vectors can be perpendicular when their dot product will be zero.
Now, $u \cdot v=(ti-j+k) \cdot (ti+tj-2k) =0\\ t^2-t-2=0$
By using the zero product property, we have: $t=2; -1$
Therefore, the two vectors u and v can be perpendicular when $t=2; -1$.
