Find the distance between two skew lines:
L1: x = 2s, y = 2s - 1, z = s + 1, and L2: x = t, y = 2t - 2, z = 3.
If $\displaystyle P+tD~\&~Q+sE$ are two skew lines, the the distance between them is $\displaystyle \frac{{\left| {\overrightarrow {PQ} \cdot \left( {D \times E} \right)} \right|}}{{\left\| {\left( {D \times E} \right)} \right\|}}$