OCR C4 — Question 5 10 marks

Exam BoardOCR
ModuleC4 (Core Mathematics 4)
Marks10
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicIntegration with Partial Fractions
TypePartial fractions with repeated linear factor
DifficultyStandard +0.3 This is a standard partial fractions question with a repeated linear factor, followed by routine integration using logarithms and the reverse chain rule. The algebraic manipulation is straightforward for C4 level, and the integration techniques are directly applicable without requiring novel insight. Slightly above average difficulty due to the repeated factor and careful arithmetic required, but remains a textbook exercise.
Spec1.02y Partial fractions: decompose rational functions1.08j Integration using partial fractions

$$f(x) = \frac{15-17x}{(2+x)(1-3x)^2}, \quad x \neq -2, \quad x \neq \frac{1}{3}.$$
  1. Find the values of the constants \(A\), \(B\) and \(C\) such that $$f(x) = \frac{A}{2+x} + \frac{B}{1-3x} + \frac{C}{(1-3x)^2}.$$ [5]
  2. Find the value of $$\int_{-1}^{0} f(x) \, dx,$$ giving your answer in the form \(p + \ln q\), where \(p\) and \(q\) are integers. [5]

$$f(x) = \frac{15-17x}{(2+x)(1-3x)^2}, \quad x \neq -2, \quad x \neq \frac{1}{3}.$$
\begin{enumerate}[label=(\roman*)]
\item Find the values of the constants $A$, $B$ and $C$ such that
$$f(x) = \frac{A}{2+x} + \frac{B}{1-3x} + \frac{C}{(1-3x)^2}.$$ [5]
\item Find the value of
$$\int_{-1}^{0} f(x) \, dx,$$
giving your answer in the form $p + \ln q$, where $p$ and $q$ are integers. [5]
\end{enumerate}

\hfill \mbox{\textit{OCR C4  Q5 [10]}}