Q. Let $A(\vec{a})$ and $B(\vec{b})$ be points on two skew line $\vec{r}=\vec{a}+\vec{\lambda}$ and $\vec{r}=\vec{b}+u \vec{q}$ and the shortest distance between the skew line is 1 , where $\vec{p}$ and $\vec{q}$ are unit vectors forming adjacent sides of a parallelogram enclosing an area of $\frac{1}{2}$ units. If an angle between $A B$ and the line of shortest distance is $60^{\circ}$, then $A B=$
Three Dimensional Geometry
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