2024 NJC Promo Q5

2024 NJC Promo Q5

10 marks
Promo

The line \({{l}_{1}}\) passes through the point \(A\left( 7,6,5 \right)\) and the point \(B\left( -5,-2,-5 \right)\) while the line \({{l}_{2}}\) has equation \(x-5=\frac{y-10}{k}=\frac{z-8}{2}\), where \(k\) is a constant. The lines \({{l}_{1}}\) and \({{l}_{2}}\) intersect at point \(P\).

  1. Show that \(k=2\) and find the coordinates of \(P\).[5]
  2. Find the position vector of the point on \({{l}_{2}}\) which is closest to \(A\).[3]
  3. Hence, find a vector equation of the line which is a reflection of \({{l}_{1}}\) in \({{l}_{2}}\).[2]

Video Solution:

Video Solution

Video solution locked

A free account saves your progress; this video needs tuition enrolment.

Solution:

Solution locked

680+ questions here come with free worked solutions. A free account saves your questions and progress; this one needs tuition enrolment.

Create a free account to practise similar questions.

Answer:(i) \(k=2\), \(P=(1,2,0)\) (ii) \(\overrightarrow{OF}=\begin{pmatrix}\frac{11}{3}\\\frac{22}{3}\\\frac{16}{3}\end{pmatrix}\) (iii) \(\mathbf r=\begin{pmatrix}1\\2\\0\end{pmatrix}+t\begin{pmatrix}-2\\20\\17\end{pmatrix}\), where \(t\in\mathbb R\)

Need help? Join our JC Math tuition classes.

Learn more