AQA FP3 2011 January — Question 3 9 marks

Exam BoardAQA
ModuleFP3 (Further Pure Mathematics 3)
Year2011
SessionJanuary
Marks9
PaperDownload PDF ↗
TopicPolar coordinates
TypeConvert Cartesian to polar equation
DifficultyStandard +0.8 This is a Further Maths polar coordinates question requiring conversion to Cartesian form (involving algebraic manipulation with r² = x² + y² and x = r cos θ), then finding intersection points with a line and calculating distance. Multi-step with moderate algebraic complexity, but follows standard techniques taught in FP3.
Spec4.09a Polar coordinates: convert to/from cartesian4.09b Sketch polar curves: r = f(theta)

3 A curve \(C\) has polar equation \(r ( 1 + \cos \theta ) = 2\).
  1. Find the cartesian equation of \(C\), giving your answer in the form \(y ^ { 2 } = \mathrm { f } ( x )\).
  2. The straight line with polar equation \(4 r = 3 \sec \theta\) intersects the curve \(C\) at the points \(P\) and \(Q\). Find the length of \(P Q\).

3 A curve $C$ has polar equation $r ( 1 + \cos \theta ) = 2$.
\begin{enumerate}[label=(\alph*)]
\item Find the cartesian equation of $C$, giving your answer in the form $y ^ { 2 } = \mathrm { f } ( x )$.
\item The straight line with polar equation $4 r = 3 \sec \theta$ intersects the curve $C$ at the points $P$ and $Q$. Find the length of $P Q$.
\end{enumerate}

\hfill \mbox{\textit{AQA FP3 2011 Q3 [9]}}