Edexcel F1 2024 January — Question 3 6 marks

Exam BoardEdexcel
ModuleF1 (Further Pure Mathematics 1)
Year2024
SessionJanuary
Marks6
PaperDownload PDF ↗
TopicConic sections
TypeParabola area calculations
DifficultyStandard +0.8 This is a Further Maths question requiring implicit differentiation of a rectangular hyperbola, finding tangent equations, determining intercepts, and using area constraints. While the techniques are standard for F1, the multi-step nature, parametric point representation, and algebraic manipulation required place it moderately above average difficulty.
Spec1.03g Parametric equations: of curves and conversion to cartesian1.07m Tangents and normals: gradient and equations1.07s Parametric and implicit differentiation

  1. The hyperbola \(H\) has equation \(x y = c ^ { 2 }\) where \(c\) is a positive constant.
The point \(P \left( c t , \frac { c } { t } \right)\), where \(t > 0\), lies on \(H\).
The tangent to \(H\) at \(P\) meets the \(x\)-axis at the point \(A\) and meets the \(y\)-axis at the point \(B\).
  1. Determine, in terms of \(c\) and \(t\),
    1. the coordinates of \(A\),
    2. the coordinates of \(B\). Given that the area of triangle \(A O B\), where \(O\) is the origin, is 90 square units,
  2. determine the value of \(c\), giving your answer as a simplified surd.

\begin{enumerate}
  \item The hyperbola $H$ has equation $x y = c ^ { 2 }$ where $c$ is a positive constant.
\end{enumerate}

The point $P \left( c t , \frac { c } { t } \right)$, where $t > 0$, lies on $H$.\\
The tangent to $H$ at $P$ meets the $x$-axis at the point $A$ and meets the $y$-axis at the point $B$.\\
(a) Determine, in terms of $c$ and $t$,\\
(i) the coordinates of $A$,\\
(ii) the coordinates of $B$.

Given that the area of triangle $A O B$, where $O$ is the origin, is 90 square units,\\
(b) determine the value of $c$, giving your answer as a simplified surd.

\hfill \mbox{\textit{Edexcel F1 2024 Q3 [6]}}