Edexcel F1 2024 January — Question 7 7 marks

Exam BoardEdexcel
ModuleF1 (Further Pure Mathematics 1)
Year2024
SessionJanuary
Marks7
PaperDownload PDF ↗
TopicConic sections
TypeParabola normal equation derivation
DifficultyStandard +0.8 This is a Further Maths question requiring implicit differentiation to find the normal equation (part a), then solving a cubic system to find the second intersection point (part b). While the calculus is standard, the parametric form and solving for the second intersection requires careful algebraic manipulation beyond typical A-level Core questions.
Spec1.03g Parametric equations: of curves and conversion to cartesian1.07m Tangents and normals: gradient and equations1.07s Parametric and implicit differentiation

  1. The parabola \(C\) has equation \(y ^ { 2 } = \frac { 4 } { 3 } x\)
The point \(P \left( \frac { 1 } { 3 } t ^ { 2 } , \frac { 2 } { 3 } t \right)\), where \(t \neq 0\), lies on \(C\).
  1. Use calculus to show that the normal to \(C\) at \(P\) has equation $$3 t x + 3 y = t ^ { 3 } + 2 t$$ The normal to \(C\) at the point where \(t = 9\) meets \(C\) again at the point \(Q\).
  2. Determine the exact coordinates of \(Q\).

\begin{enumerate}
  \item The parabola $C$ has equation $y ^ { 2 } = \frac { 4 } { 3 } x$
\end{enumerate}

The point $P \left( \frac { 1 } { 3 } t ^ { 2 } , \frac { 2 } { 3 } t \right)$, where $t \neq 0$, lies on $C$.\\
(a) Use calculus to show that the normal to $C$ at $P$ has equation

$$3 t x + 3 y = t ^ { 3 } + 2 t$$

The normal to $C$ at the point where $t = 9$ meets $C$ again at the point $Q$.\\
(b) Determine the exact coordinates of $Q$.

\hfill \mbox{\textit{Edexcel F1 2024 Q7 [7]}}