Relative to a fixed origin OOO, the path of a high-precision industrial laser cutter LLL is described by the vector equation
r=(3−24)+λ(12−2) \mathbf{r} = \begin{pmatrix} 3 \\ -2 \\ 4 \end{pmatrix} + \lambda \begin{pmatrix} 1 \\ 2 \\ -2 \end{pmatrix} r=3−24+λ12−2where λ\lambdaλ is a scalar parameter.
Given that OA→\overrightarrow{OA}OA is a unit vector parallel to the path LLL,
find OA→\overrightarrow{OA}OA.
The point XXX lies on the path LLL such that it is the closest point on the path to the origin OOO.
Find the coordinates of XXX.
Points OOO, XXX, and AAA form a triangle OXAOXAOXA.
Determine the exact area of triangle OXAOXAOXA.
109 exam-style questions on Edexcel A Level Maths Vectors, covering 12.1 3D Coordinates, 12.2 Vectors in 3D, 12.3 Solving Geometric Problems, and 12.4 Application to Mechanics. Each one has a worked solution and a mark scheme showing where the marks go.