CAIE P2 2017 November — Question 4 8 marks

Exam BoardCAIE
ModuleP2 (Pure Mathematics 2)
Year2017
SessionNovember
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicStandard Integrals and Reverse Chain Rule
DifficultyStandard +0.3 Part (a) requires recognizing the Pythagorean identity sin²θ + cos²θ = 1 to simplify the integrand, then splitting into standard integrals. Part (b) is a straightforward logarithmic integration with algebraic manipulation. Both parts are routine applications of standard techniques with no novel problem-solving required, making this slightly easier than average.
Spec1.06g Equations with exponentials: solve a^x = b1.08c Integrate e^(kx), 1/x, sin(kx), cos(kx)

4
  1. Find \(\int \frac { 4 + \sin ^ { 2 } \theta } { 1 - \sin ^ { 2 } \theta } \mathrm {~d} \theta\).
  2. Given that \(\int _ { 0 } ^ { a } \frac { 2 } { 3 x + 1 } \mathrm {~d} x = \ln 16\), find the value of the positive constant \(a\).

Question 4(a):
AnswerMarks Guidance
AnswerMarks Guidance
Obtain integrand of form \(a\sec^2\theta + b\)M1
Obtain correct \(5\sec^2\theta - 1\)A1
Integrate to obtain form \(a\tan\theta + b\theta\)M1
Obtain \(5\tan\theta - \theta + c\)A1
Question 4(b):
AnswerMarks Guidance
AnswerMarks Guidance
Obtain integral of form \(k\ln(3x+1)\)\*M1
Apply limits and obtain \(\frac{2}{3}\ln(3a+1) = \ln 16\)A1
Obtain equation with no presence of \(\ln\)DM1
Obtain \(21\)A1
## Question 4(a):

| Answer | Marks | Guidance |
|--------|-------|----------|
| Obtain integrand of form $a\sec^2\theta + b$ | M1 | |
| Obtain correct $5\sec^2\theta - 1$ | A1 | |
| Integrate to obtain form $a\tan\theta + b\theta$ | M1 | |
| Obtain $5\tan\theta - \theta + c$ | A1 | |

## Question 4(b):

| Answer | Marks | Guidance |
|--------|-------|----------|
| Obtain integral of form $k\ln(3x+1)$ | \*M1 | |
| Apply limits and obtain $\frac{2}{3}\ln(3a+1) = \ln 16$ | A1 | |
| Obtain equation with no presence of $\ln$ | DM1 | |
| Obtain $21$ | A1 | |

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4
\begin{enumerate}[label=(\alph*)]
\item Find $\int \frac { 4 + \sin ^ { 2 } \theta } { 1 - \sin ^ { 2 } \theta } \mathrm {~d} \theta$.
\item Given that $\int _ { 0 } ^ { a } \frac { 2 } { 3 x + 1 } \mathrm {~d} x = \ln 16$, find the value of the positive constant $a$.
\end{enumerate}

\hfill \mbox{\textit{CAIE P2 2017 Q4 [8]}}