(i)[5]
Use the scalar product method to determine angle $OAB$.
(ii)[2]
Determine the area of triangle $OAB$.
Mathematics 9709 · AS & A Level · Coordinate geometry
Coordinate geometry — practice question
Taking origin $O$ as the reference point, the position vectors of $A$ and $B$ are $overrightarrow{OA} = 2\mathbf{i} + 3\mathbf{j} + 5\mathbf{k}$ and $\overrightarrow{OB} = 7\mathbf{i} + 4\mathbf{j} + 3\mathbf{k}$.