2024 CJC Promo Q7

2024 CJC Promo Q7

7 marks
Promo
  1. Three non-zero vectors \(\mathbf{p}\), \(\mathbf{q}\) and \(\mathbf{r}\) are such that \(3\mathbf{p}\times \mathbf{q}=\mathbf{r}\times \mathbf{p}\).
    Find a linear relationship between \(\mathbf{p}\), \(\mathbf{q}\) and \(\mathbf{r}\).[3]
  2. Referred to the origin \(O\), the points \(A\) and \(B\) have position vectors \(\mathbf{a}\) and \(\mathbf{b}\).
    It is given that \(\mathbf{a}\) and \(\mathbf{b}\) are non-parallel unit vectors.
    The point \(B\) divides \(AC\) in the ratio \(1:3\).
    The point \(D\) lies on \(OB\) produced such that \(OB:OD=1:m\); \(m\in \mathbb{Z}\); \(m\ge 2\).
    Given that \(\overrightarrow{AB}\) is perpendicular to \(\overrightarrow{CD}\), find the numerical value of \(m\).[4]

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:(a) \(\mathbf{p}=k\left( 3\mathbf{q}+\mathbf{r} \right)\); \(k\in \mathbb{R}\backslash \left\{ 0 \right\}\) (b) \(m=7\)

Need help? Join our JC Math tuition classes.

Learn more