Edexcel C2 2018 June — Question 9 12 marks

Exam BoardEdexcel
ModuleC2 (Core Mathematics 2)
Year2018
SessionJune
Marks12
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicStationary points and optimisation
TypeFind stationary points coordinates
DifficultyStandard +0.3 This is a straightforward C2 question requiring standard techniques: differentiate using product/chain rule, find stationary point by setting derivative to zero, find x-intercept by solving algebraic equation, and integrate using power rule. All steps are routine applications of core techniques with no novel problem-solving required, making it slightly easier than average.
Spec1.07n Stationary points: find maxima, minima using derivatives1.08e Area between curve and x-axis: using definite integrals

9. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{8daf56fa-bfce-454e-bbb8-fecd8170d77e-28_751_876_214_539} \captionsetup{labelformat=empty} \caption{Figure 3}
\end{figure} Figure 3 shows a sketch of part of the curve with equation $$y = 7 x ^ { 2 } ( 5 - 2 \sqrt { x } ) , \quad x \geqslant 0$$ The curve has a turning point at the point \(A\), where \(x > 0\), as shown in Figure 3.
  1. Using calculus, find the coordinates of the point \(A\). The curve crosses the \(x\)-axis at the point \(B\), as shown in Figure 3.
  2. Use algebra to find the \(x\) coordinate of the point \(B\). The finite region \(R\), shown shaded in Figure 3, is bounded by the curve, the line through \(A\) parallel to the \(x\)-axis and the line through \(B\) parallel to the \(y\)-axis.
  3. Use integration to find the area of the region \(R\), giving your answer to 2 decimal places.
    END

9.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{8daf56fa-bfce-454e-bbb8-fecd8170d77e-28_751_876_214_539}
\captionsetup{labelformat=empty}
\caption{Figure 3}
\end{center}
\end{figure}

Figure 3 shows a sketch of part of the curve with equation

$$y = 7 x ^ { 2 } ( 5 - 2 \sqrt { x } ) , \quad x \geqslant 0$$

The curve has a turning point at the point $A$, where $x > 0$, as shown in Figure 3.
\begin{enumerate}[label=(\alph*)]
\item Using calculus, find the coordinates of the point $A$.

The curve crosses the $x$-axis at the point $B$, as shown in Figure 3.
\item Use algebra to find the $x$ coordinate of the point $B$.

The finite region $R$, shown shaded in Figure 3, is bounded by the curve, the line through $A$ parallel to the $x$-axis and the line through $B$ parallel to the $y$-axis.
\item Use integration to find the area of the region $R$, giving your answer to 2 decimal places.\\

\begin{center}
\begin{tabular}{|l|l|}
\hline

\hline
END &  \\
\hline
\end{tabular}
\end{center}
\end{enumerate}

\hfill \mbox{\textit{Edexcel C2 2018 Q9 [12]}}