Mathematics 9709 · AS & A Level · Vectors

Vectors — practice question

The diagram depicts three points $A$, $B$ and $C$, with position vectors relative to the origin $O$ given by $\vec{OA} = \begin{pmatrix}2 \\ -1 \\ 2\end{pmatrix}$, $\vec{OB} = \begin{pmatrix}0 \\ 3 \\ 1\end{pmatrix}$ and $\vec{OC} = \begin{pmatrix}3 \\ 0 \\ 4\end{pmatrix}$. Point $D$ is situated on $BC$, between $B$ and $C$, and satisfies $CD = 2DB$.
(i)[6]

Find the equation of plane $ABC$, and give your answer in the form $ax + by + cz = d$.

(ii)[1]

Find the position vector for $D$.

(iii)[4]

Show that the perpendicular distance from $A$ to $OD$ is $\frac{1}{3} \sqrt{65}$.

Worked solution & mark scheme

This 11-mark question has a full step-by-step worked solution and mark scheme. One marking point: Obtain a vector lying parallel to the plane

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