Edexcel PURE 2024 October — Question 9

Exam BoardEdexcel
ModulePURE
Year2024
SessionOctober
PaperDownload PDF ↗
TopicCurve Sketching
TypeTransformation effect on key points
DifficultyModerate -0.3 This is a multi-part question covering standard A-level techniques: reading a graph for inequalities, differentiating a product, finding parallel tangents, and applying transformations. All parts are routine applications of core methods with no novel problem-solving required, making it slightly easier than average.
Spec1.02j Manipulate polynomials: expanding, factorising, division, factor theorem1.02w Graph transformations: simple transformations of f(x)1.07i Differentiate x^n: for rational n and sums1.07q Product and quotient rules: differentiation

9. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{c48e6503-9d26-4f55-bdca-feadfb1afb7c-26_732_730_251_669} \captionsetup{labelformat=empty} \caption{Figure 4}
\end{figure} Figure 4 shows a sketch of the curve \(C\) with equation \(y = \mathrm { f } ( x )\), where $$f ( x ) = ( x + 5 ) \left( 3 x ^ { 2 } - 4 x + 20 \right)$$
  1. Deduce the range of values of \(x\) for which \(\mathrm { f } ( x ) \geqslant 0\)
  2. Find \(\mathrm { f } ^ { \prime } ( x )\) giving your answer in simplest form. The point \(R ( - 4,84 )\) lies on \(C\).
    Given that the tangent to \(C\) at the point \(P\) is parallel to the tangent to \(C\) at the point \(R\) (c) find the \(x\) coordinate of \(P\).
    (d) Find the point to which \(R\) is transformed when the curve with equation \(y = \mathrm { f } ( x )\) is transformed to the curve with equation,
    1. \(y = \mathrm { f } ( x - 3 )\)
    2. \(y = 4 \mathrm { f } ( x )\)

9.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{c48e6503-9d26-4f55-bdca-feadfb1afb7c-26_732_730_251_669}
\captionsetup{labelformat=empty}
\caption{Figure 4}
\end{center}
\end{figure}

Figure 4 shows a sketch of the curve $C$ with equation $y = \mathrm { f } ( x )$, where

$$f ( x ) = ( x + 5 ) \left( 3 x ^ { 2 } - 4 x + 20 \right)$$
\begin{enumerate}[label=(\alph*)]
\item Deduce the range of values of $x$ for which $\mathrm { f } ( x ) \geqslant 0$
\item Find $\mathrm { f } ^ { \prime } ( x )$ giving your answer in simplest form.

The point $R ( - 4,84 )$ lies on $C$.\\
Given that the tangent to $C$ at the point $P$ is parallel to the tangent to $C$ at the point $R$ (c) find the $x$ coordinate of $P$.\\
(d) Find the point to which $R$ is transformed when the curve with equation $y = \mathrm { f } ( x )$ is transformed to the curve with equation,
\begin{enumerate}[label=(\roman*)]
\item $y = \mathrm { f } ( x - 3 )$
\item $y = 4 \mathrm { f } ( x )$
\end{enumerate}\end{enumerate}

\hfill \mbox{\textit{Edexcel PURE 2024 Q9}}