OCR MEI C3 — Question 8 17 marks

Exam BoardOCR MEI
ModuleC3 (Core Mathematics 3)
Marks17
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicAreas by integration
TypeArea between curve and line
DifficultyStandard +0.3 This is a structured multi-part question testing standard C3 techniques: solving sin equations, product rule differentiation, showing tangency by comparing gradients, and integration by parts. While part (iv) requires careful setup and integration by parts twice, each step follows predictable methods with clear guidance. The question is slightly above average due to the integration by parts component, but remains a typical exam question without requiring novel insight.
Spec1.05k Further identities: sec^2=1+tan^2 and cosec^2=1+cot^21.07q Product and quotient rules: differentiation1.08f Area between two curves: using integration1.08i Integration by parts

Fig. 8 shows part of the curve \(y = x \sin 3x\). It crosses the \(x\)-axis at P. The point on the curve with \(x\)-coordinate \(\frac{1}{6}\pi\) is Q. \includegraphics{figure_8}
  1. Find the \(x\)-coordinate of P. [3]
  2. Show that Q lies on the line \(y = x\). [1]
  3. Differentiate \(x \sin 3x\). Hence prove that the line \(y = x\) touches the curve at Q. [6]
  4. Show that the area of the region bounded by the curve and the line \(y = x\) is \(\frac{1}{72}(\pi^2 - 8)\). [7]

Fig. 8 shows part of the curve $y = x \sin 3x$. It crosses the $x$-axis at P. The point on the curve with $x$-coordinate $\frac{1}{6}\pi$ is Q.

\includegraphics{figure_8}

\begin{enumerate}[label=(\roman*)]
\item Find the $x$-coordinate of P. [3]
\item Show that Q lies on the line $y = x$. [1]
\item Differentiate $x \sin 3x$. Hence prove that the line $y = x$ touches the curve at Q. [6]
\item Show that the area of the region bounded by the curve and the line $y = x$ is $\frac{1}{72}(\pi^2 - 8)$. [7]
\end{enumerate}

\hfill \mbox{\textit{OCR MEI C3  Q8 [17]}}