# Math Help - distance between two skew lines.

1. ## distance between two skew lines.

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.

2. Originally Posted by qkfxjs
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 $P+tD~\&~Q+sE$ are two skew lines, the the distance between them is $\frac{{\left| {\overrightarrow {PQ} \cdot \left( {D \times E} \right)} \right|}}{{\left\| {\left( {D \times E} \right)} \right\|}}$

3. ## Ok

So how can I solve the problem.

I'm still having a problem.

4. Originally Posted by qkfxjs
So how can I solve the problem.
Find the direction vector of each line. Those are $D~\&~E$.

Find a point on each line. Those are $P~\&~Q$

Then use the formula.