CAIE P2 2023 November — Question 5 8 marks

Exam BoardCAIE
ModuleP2 (Pure Mathematics 2)
Year2023
SessionNovember
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicStandard Integrals and Reverse Chain Rule
TypePolynomial division before integration
DifficultyModerate -0.3 This is a straightforward two-part question requiring polynomial long division followed by integration of the resulting polynomial plus a logarithmic term. Both techniques are standard P2 procedures with no novel insight required, making it slightly easier than average but still requiring careful algebraic manipulation across multiple steps.
Spec1.02k Simplify rational expressions: factorising, cancelling, algebraic division1.08c Integrate e^(kx), 1/x, sin(kx), cos(kx)

5
  1. Find the quotient when \(6 x ^ { 3 } - 5 x ^ { 2 } - 24 x - 4\) is divided by ( \(2 x + 1\) ), and show that the remainder is 6 .
  2. Hence find $$\int _ { 2 } ^ { 7 } \frac { 6 x ^ { 3 } - 5 x ^ { 2 } - 24 x - 4 } { 2 x + 1 } d x$$ 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 OE (e.g. by inspection)
Obtain quotient \(3x^2-4x-10\)A1
Confirm given result of remainder is 6 with sufficient detailA1 AG. SC If remainder \(=6\) shown using remainder theorem allow B1
Question 5(b):
AnswerMarks Guidance
AnswerMarks Guidance
Integrate to obtain at least \(x^3\) and term of form \(k_2\ln(2x+1)\)*M1 ln term must be added
Obtain \(x^3-2x^2-10x+3\ln(2x+1)\)A1
Apply limits correctly to expression with four termsDM1
Apply appropriate logarithm properties correctly to obtain the form \(k_3\ln a\)DM1
Obtain \(195+\ln 27\)A1
## Question 5(a):

| Answer | Marks | Guidance |
|--------|-------|----------|
| Carry out division at least as far as $3x^2+k_1x$ | M1 | OE (e.g. by inspection) |
| Obtain quotient $3x^2-4x-10$ | A1 | |
| Confirm given result of remainder is 6 with sufficient detail | A1 | AG. SC If remainder $=6$ shown using remainder theorem allow B1 |

## Question 5(b):

| Answer | Marks | Guidance |
|--------|-------|----------|
| Integrate to obtain at least $x^3$ and term of form $k_2\ln(2x+1)$ | *M1 | ln term must be added |
| Obtain $x^3-2x^2-10x+3\ln(2x+1)$ | A1 | |
| Apply limits correctly to expression with four terms | DM1 | |
| Apply appropriate logarithm properties correctly to obtain the form $k_3\ln a$ | DM1 | |
| Obtain $195+\ln 27$ | A1 | |
5
\begin{enumerate}[label=(\alph*)]
\item Find the quotient when $6 x ^ { 3 } - 5 x ^ { 2 } - 24 x - 4$ is divided by ( $2 x + 1$ ), and show that the remainder is 6 .
\item Hence find

$$\int _ { 2 } ^ { 7 } \frac { 6 x ^ { 3 } - 5 x ^ { 2 } - 24 x - 4 } { 2 x + 1 } d x$$

giving your answer in the form $a + \ln b$, where $a$ and $b$ are integers.
\end{enumerate}

\hfill \mbox{\textit{CAIE P2 2023 Q5 [8]}}