Edexcel C4 — Question 18 7 marks

Exam BoardEdexcel
ModuleC4 (Core Mathematics 4)
Marks7
PaperDownload PDF ↗
TopicIntegration by Parts
TypeBasic integration by parts
DifficultyModerate -0.3 Part (a) is a standard integration by parts exercise with a straightforward choice of u and dv, requiring only routine application of the formula. Part (b) adds a mild algebraic verification step using double-angle identities, but this is still within typical C4 expectations. The question is slightly easier than average due to its predictable structure and limited conceptual demand.
Spec1.05l Double angle formulae: and compound angle formulae1.08i Integration by parts

  1. Use integration by parts to find $$\int x \cos 2x \, dx.$$ [4]
  2. Prove that the answer to part \((a)\) may be expressed as $$\frac{1}{2} \sin x (2x \cos x - \sin x) + C,$$ where \(C\) is an arbitrary constant. [3]

\begin{enumerate}[label=(\alph*)]
\item Use integration by parts to find
$$\int x \cos 2x \, dx.$$ [4]

\item Prove that the answer to part $(a)$ may be expressed as
$$\frac{1}{2} \sin x (2x \cos x - \sin x) + C,$$
where $C$ is an arbitrary constant. [3]
\end{enumerate}

\hfill \mbox{\textit{Edexcel C4  Q18 [7]}}