WJEC Unit 3 2023 June — Question 8 7 marks

Exam BoardWJEC
ModuleUnit 3 (Unit 3)
Year2023
SessionJune
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicIndefinite & Definite Integrals
TypeIntegration with partial fractions
DifficultyStandard +0.3 This is a straightforward algebraic manipulation followed by a standard integration. Part (a) requires factorising and simplifying a rational function (routine A-level algebra), and part (b) applies direct integration of a simple form with logarithms. The question is slightly easier than average as it's highly structured with clear guidance ('show that' and 'hence'), requiring no problem-solving insight beyond standard techniques.
Spec1.02k Simplify rational expressions: factorising, cancelling, algebraic division1.08d Evaluate definite integrals: between limits

The function \(f\) is defined by \(f(x) = \frac{4x^2 + 12x + 9}{2x^2 + x - 3}\), where \(x > 1\).
  1. Show that \(f(x)\) can be written as \(2 + \frac{5}{x-1}\). [3]
  2. Hence find the exact value of \(\int_3^7 f(x)\,dx\). [4]

The function $f$ is defined by $f(x) = \frac{4x^2 + 12x + 9}{2x^2 + x - 3}$, where $x > 1$.

\begin{enumerate}[label=(\alph*)]
\item Show that $f(x)$ can be written as $2 + \frac{5}{x-1}$. [3]

\item Hence find the exact value of $\int_3^7 f(x)\,dx$. [4]
\end{enumerate}

\hfill \mbox{\textit{WJEC Unit 3 2023 Q8 [7]}}