Edexcel F1 2022 June — Question 6 11 marks

Exam BoardEdexcel
ModuleF1 (Further Pure Mathematics 1)
Year2022
SessionJune
Marks11
PaperDownload PDF ↗
TopicConic sections
TypeParabola normal intersection problems
DifficultyChallenging +1.3 This is a structured Further Maths parabola question with clear scaffolding. Part (a) is routine calculus (finding normal equation using parametric form), part (b) requires solving a cubic for parameter values, and part (c) combines focus/directrix properties with coordinate geometry. While it requires multiple techniques and is longer than typical A-level questions, the scaffolding guides students through each step without requiring significant novel insight or problem-solving creativity.
Spec1.03f Circle properties: angles, chords, tangents1.03g Parametric equations: of curves and conversion to cartesian1.07s Parametric and implicit differentiation

  1. The parabola \(C\) has equation \(y ^ { 2 } = 36 x\)
The point \(P \left( 9 t ^ { 2 } , 18 t \right)\), where \(t \neq 0\), lies on \(C\)
  1. Use calculus to show that the normal to \(C\) at \(P\) has equation $$y + t x = 9 t ^ { 3 } + 18 t$$
  2. Hence find the equations of the two normals to \(C\) which pass through the point (54, 0), giving your answers in the form \(y = p x + q\) where \(p\) and \(q\) are constants to be determined. Given that
    • the normals found in part (b) intersect the directrix of \(C\) at the points \(A\) and \(B\)
    • the point \(F\) is the focus of \(C\)
    • determine the area of triangle \(A F B\)

\begin{enumerate}
  \item The parabola $C$ has equation $y ^ { 2 } = 36 x$
\end{enumerate}

The point $P \left( 9 t ^ { 2 } , 18 t \right)$, where $t \neq 0$, lies on $C$\\
(a) Use calculus to show that the normal to $C$ at $P$ has equation

$$y + t x = 9 t ^ { 3 } + 18 t$$

(b) Hence find the equations of the two normals to $C$ which pass through the point (54, 0), giving your answers in the form $y = p x + q$ where $p$ and $q$ are constants to be determined.

Given that

\begin{itemize}
  \item the normals found in part (b) intersect the directrix of $C$ at the points $A$ and $B$
  \item the point $F$ is the focus of $C$\\
(c) determine the area of triangle $A F B$
\end{itemize}

\hfill \mbox{\textit{Edexcel F1 2022 Q6 [11]}}