First, find the vector equation of the line passing through A and B. The direction vector \(\overrightarrow{AB}\) is given by:
\(\overrightarrow{AB} = \overrightarrow{OB} - \overrightarrow{OA} = (\mathbf{i} + \mathbf{j} + 5\mathbf{k}) - (2\mathbf{i} - \mathbf{j} + 3\mathbf{k}) = -\mathbf{i} + 2\mathbf{j} + 2\mathbf{k}\)
The vector equation of the line through A and B is:
\(\mathbf{r} = 2\mathbf{i} - \mathbf{j} + 3\mathbf{k} + \lambda(-\mathbf{i} + 2\mathbf{j} + 2\mathbf{k})\)
Equate the components of the general points on both lines:
\(2 - \lambda = 1 + 3\mu\)
\(-1 + 2\lambda = 1 + \mu\)
\(3 + 2\lambda = 2 - \mu\)
Solve these equations for \(\lambda\) and \(\mu\):
From the first equation: \(\lambda = 1 - 3\mu\)
Substitute into the second equation:
\(-1 + 2(1 - 3\mu) = 1 + \mu\)
\(-1 + 2 - 6\mu = 1 + \mu\)
\(-6\mu - \mu = 1\)
\(-7\mu = 0\)
\(\mu = 0\)
Substitute \(\mu = 0\) into \(\lambda = 1 - 3\mu\):
\(\lambda = 1\)
Check the third equation:
\(3 + 2(1) = 2 - 0\)
\(5 \neq 2\)
Since not all three equations are satisfied, the lines do not intersect.