CAIE P2 2024 June — Question 5 8 marks

Exam BoardCAIE
ModuleP2 (Pure Mathematics 2)
Year2024
SessionJune
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicPolynomial Division & Manipulation
TypeIntegration Using Polynomial Division
DifficultyStandard +0.3 This is a straightforward two-part question requiring polynomial long division followed by integration of the resulting quotient plus remainder term. Part (a) is routine algebraic manipulation, and part (b) involves standard integration techniques (polynomial terms plus logarithmic integration). The question is slightly easier than average as it guides students through the process and requires only well-practiced A-level techniques with no novel problem-solving.
Spec1.02j Manipulate polynomials: expanding, factorising, division, factor theorem1.08j Integration using partial fractions

5 The polynomial \(\mathrm { p } ( x )\) is defined by \(\mathrm { p } ( x ) = 9 x ^ { 3 } + 18 x ^ { 2 } + 5 x + 4\).
  1. Find the quotient when \(\mathrm { p } ( x )\) is divided by \(( 3 x + 2 )\), and show that the remainder is 6 . \includegraphics[max width=\textwidth, alt={}, center]{76df3465-9617-4f2b-a8b7-f474b2817504-08_2713_33_146_2012} \includegraphics[max width=\textwidth, alt={}, center]{76df3465-9617-4f2b-a8b7-f474b2817504-09_2723_33_138_20}
  2. Find the value of \(\int _ { 0 } ^ { 2 } \frac { \mathrm { p } ( x ) } { 3 x + 2 } \mathrm {~d} x\) ,giving your answer in the form \(a + \ln b\) where \(a\) and \(b\) are integers.

Question 5(a):
AnswerMarks Guidance
AnswerMarks Guidance
Carry out division at least as far as \(3x^2 + k_1x\)M1 Or equivalent (inspection, …)
Obtain quotient \(3x^2 + 4x - 1\)A1
Confirm remainder is \(6\)A1 Answer given – necessary detail needed. SC B1 for use of factor theorem to show remainder is 6 if no other marks awarded
Alternative Method 5(a) — Synthetic division:
AnswerMarks Guidance
AnswerMarks Guidance
Synthetic division: \(-\frac{2}{3}\) \\(9\) \ \(18\) \
Obtain quotient \(3x^2 + 4x - 1\)(A1)
Confirm remainder is \(6\)(A1)
Question 5(b):
AnswerMarks Guidance
AnswerMarks Guidance
Identify integrand as \(3x^2 + 4x - 1 + \frac{6}{3x+2}\)B1 FT Following *their* quotient
Integrate to obtain at least \(x^3\) and \(k_2\ln(3x+2)\) terms*M1
Obtain \(x^3 + 2x^2 - x + 2\ln(3x+2)\)A1
Apply limits and appropriate logarithm propertiesDM1
Obtain \(14 + \ln 16\)A1
## Question 5(a):

| Answer | Marks | Guidance |
|--------|-------|----------|
| Carry out division at least as far as $3x^2 + k_1x$ | M1 | Or equivalent (inspection, …) |
| Obtain quotient $3x^2 + 4x - 1$ | A1 | |
| Confirm remainder is $6$ | A1 | Answer given – necessary detail needed. SC B1 for use of factor theorem to show remainder is 6 if no other marks awarded |

**Alternative Method 5(a) — Synthetic division:**

| Answer | Marks | Guidance |
|--------|-------|----------|
| Synthetic division: $-\frac{2}{3}$ \| $9$ \| $18$ \| $5$ \| $4$ → row: $-6$, $8$, $-2$ → result: $9$, $12$, $-3$, $6$ | (M1) | |
| Obtain quotient $3x^2 + 4x - 1$ | (A1) | |
| Confirm remainder is $6$ | (A1) | |

## Question 5(b):

| Answer | Marks | Guidance |
|--------|-------|----------|
| Identify integrand as $3x^2 + 4x - 1 + \frac{6}{3x+2}$ | B1 FT | Following *their* quotient |
| Integrate to obtain at least $x^3$ and $k_2\ln(3x+2)$ terms | *M1 | |
| Obtain $x^3 + 2x^2 - x + 2\ln(3x+2)$ | A1 | |
| Apply limits and appropriate logarithm properties | DM1 | |
| Obtain $14 + \ln 16$ | A1 | |
5 The polynomial $\mathrm { p } ( x )$ is defined by $\mathrm { p } ( x ) = 9 x ^ { 3 } + 18 x ^ { 2 } + 5 x + 4$.
\begin{enumerate}[label=(\alph*)]
\item Find the quotient when $\mathrm { p } ( x )$ is divided by $( 3 x + 2 )$, and show that the remainder is 6 .\\

\includegraphics[max width=\textwidth, alt={}, center]{76df3465-9617-4f2b-a8b7-f474b2817504-08_2713_33_146_2012}\\
\includegraphics[max width=\textwidth, alt={}, center]{76df3465-9617-4f2b-a8b7-f474b2817504-09_2723_33_138_20}
\item Find the value of $\int _ { 0 } ^ { 2 } \frac { \mathrm { p } ( x ) } { 3 x + 2 } \mathrm {~d} x$ ,giving your answer in the form $a + \ln b$ where $a$ and $b$ are integers.
\end{enumerate}

\hfill \mbox{\textit{CAIE P2 2024 Q5 [8]}}