9709 P33 - Jun 2016 - Q8
2151
The points A and B have position vectors, relative to the origin O, given by \(\overrightarrow{OA} = \mathbf{i} + \mathbf{j} + \mathbf{k}\) and \(\overrightarrow{OB} = 2\mathbf{i} + 3\mathbf{k}\). The line \(l\) has vector equation \(\mathbf{r} = 2\mathbf{i} - 2\mathbf{j} - \mathbf{k} + \mu(-\mathbf{i} + 2\mathbf{j} + \mathbf{k})\).
(i) Show that the line passing through A and B does not intersect \(l\).
(ii) Show that the length of the perpendicular from A to \(l\) is \(\frac{1}{\sqrt{2}}\).
