CAIE P3 2014 November — Question 10

Exam BoardCAIE
ModuleP3 (Pure Mathematics 3)
Year2014
SessionNovember
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicVectors: Cross Product & Distances

10 The line \(l\) has equation \(\mathbf { r } = 4 \mathbf { i } - 9 \mathbf { j } + 9 \mathbf { k } + \lambda ( - 2 \mathbf { i } + \mathbf { j } - 2 \mathbf { k } )\). The point \(A\) has position vector \(3 \mathbf { i } + 8 \mathbf { j } + 5 \mathbf { k }\).
  1. Show that the length of the perpendicular from \(A\) to \(l\) is 15 .
  2. The line \(l\) lies in the plane with equation \(a x + b y - 3 z + 1 = 0\), where \(a\) and \(b\) are constants. Find the values of \(a\) and \(b\).

10 The line $l$ has equation $\mathbf { r } = 4 \mathbf { i } - 9 \mathbf { j } + 9 \mathbf { k } + \lambda ( - 2 \mathbf { i } + \mathbf { j } - 2 \mathbf { k } )$. The point $A$ has position vector $3 \mathbf { i } + 8 \mathbf { j } + 5 \mathbf { k }$.\\
(i) Show that the length of the perpendicular from $A$ to $l$ is 15 .\\
(ii) The line $l$ lies in the plane with equation $a x + b y - 3 z + 1 = 0$, where $a$ and $b$ are constants. Find the values of $a$ and $b$.

\hfill \mbox{\textit{CAIE P3 2014 Q10}}