Edexcel C4 — Question 5 11 marks

Exam BoardEdexcel
ModuleC4 (Core Mathematics 4)
Marks11
PaperDownload PDF ↗
TopicIntegration by Parts
TypeIndependent multi-part (different techniques)
DifficultyStandard +0.3 This is a straightforward multi-part C4 question testing standard techniques: integration by parts with a given answer to verify (reducing difficulty), volume of revolution using a formula, and product/chain rule differentiation. All parts are routine applications with no novel problem-solving required, making it slightly easier than average.
Spec1.07q Product and quotient rules: differentiation1.08i Integration by parts4.08d Volumes of revolution: about x and y axes

  1. Use integration by parts to show that $$\int_0^{\frac{\pi}{4}} x \sec^2 x \, dx = \frac{1}{4}\pi - \frac{1}{2}\ln 2.$$ [6]
\includegraphics{figure_1} The finite region \(R\), bounded by the equation \(y = x^{\frac{1}{2}} \sec x\), the line \(x = \frac{\pi}{4}\) and the \(x\)-axis is shown in Fig. 1. The region \(R\) is rotated through \(2\pi\) radians about the \(x\)-axis.
  1. Find the volume of the solid of revolution generated. [2]
  2. Find the gradient of the curve with equation \(y = x^{\frac{1}{2}} \sec x\) at the point where \(x = \frac{\pi}{4}\). [3]

\begin{enumerate}[label=(\alph*)]
\item Use integration by parts to show that
$$\int_0^{\frac{\pi}{4}} x \sec^2 x \, dx = \frac{1}{4}\pi - \frac{1}{2}\ln 2.$$ [6]
\end{enumerate}

\includegraphics{figure_1}

The finite region $R$, bounded by the equation $y = x^{\frac{1}{2}} \sec x$, the line $x = \frac{\pi}{4}$ and the $x$-axis is shown in Fig. 1. The region $R$ is rotated through $2\pi$ radians about the $x$-axis.

\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{1}
\item Find the volume of the solid of revolution generated. [2]

\item Find the gradient of the curve with equation $y = x^{\frac{1}{2}} \sec x$ at the point where $x = \frac{\pi}{4}$. [3]
\end{enumerate}

\hfill \mbox{\textit{Edexcel C4  Q5 [11]}}