SPS SPS FM Pure 2024 February — Question 6 7 marks

Exam BoardSPS
ModuleSPS FM Pure (SPS FM Pure)
Year2024
SessionFebruary
Marks7
TopicIntegration with Partial Fractions
TypeImproper integrals with partial fractions (infinite limit)
DifficultyStandard +0.3 This is a straightforward Further Maths improper integral question. Part (a) requires simple recall (infinite upper limit). Part (b) involves routine partial fractions, integration of 1/x terms, and evaluating a limit as the upper bound tends to infinity—all standard techniques with no novel insight required. The 7 total marks reflect mechanical steps rather than conceptual difficulty, making this easier than average.
Spec4.08c Improper integrals: infinite limits or discontinuous integrands

  1. Explain why \(\int_1^\infty \frac{1}{x(2x + 5)} dx\) is an improper integral. [1]
  2. Prove that $$\int_1^\infty \frac{1}{x(2x + 5)} dx = a \ln b$$ where \(a\) and \(b\) are rational numbers to be determined. [6]

\begin{enumerate}[label=(\alph*)]
\item Explain why $\int_1^\infty \frac{1}{x(2x + 5)} dx$ is an improper integral. [1]
\item Prove that 
$$\int_1^\infty \frac{1}{x(2x + 5)} dx = a \ln b$$
where $a$ and $b$ are rational numbers to be determined. [6]
\end{enumerate}

\hfill \mbox{\textit{SPS SPS FM Pure 2024 Q6 [7]}}