CAIE P2 2023 March — Question 6 8 marks

Exam BoardCAIE
ModuleP2 (Pure Mathematics 2)
Year2023
SessionMarch
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicDifferentiating Transcendental Functions
TypeFind gradient at a point - direct evaluation
DifficultyStandard +0.3 This is a straightforward differentiation question using the quotient rule on an exponential function, followed by finding a stationary point by setting the derivative to zero. Both parts are standard textbook exercises requiring routine application of techniques with no novel insight, making it slightly easier than average.
Spec1.06a Exponential function: a^x and e^x graphs and properties1.07j Differentiate exponentials: e^(kx) and a^(kx)1.07n Stationary points: find maxima, minima using derivatives

\includegraphics{figure_6} The diagram shows the curve with equation \(y = \frac{4e^{2x} + 9}{e^x + 2}\). The curve has a minimum point \(M\) and crosses the \(y\)-axis at the point \(P\).
  1. Find the exact value of the gradient of the curve at \(P\). [4]
  2. Find the exact coordinates of \(M\). [4]

Question 6:
AnswerMarks
6Recovery within working is allowed, e.g. a notation error in the working where the following line of working makes the candidate’s intent clear.
PMT
9709/22 Cambridge International AS Level – Mark Scheme February/March 2023
PUBLISHED
Abbreviations
AEF/OE Any Equivalent Form (of answer is equally acceptable) / Or Equivalent
AG Answer Given on the question paper (so extra checking is needed to ensure that the detailed working leading to the result is valid)
CAO Correct Answer Only (emphasising that no ‘follow through’ from a previous error is allowed)
CWO Correct Working Only
ISW Ignore Subsequent Working
SOI Seen Or Implied
SC Special Case (detailing the mark to be given for a specific wrong solution, or a case where some standard marking practice is to be varied in the
light of a particular circumstance)
WWW Without Wrong Working
AWRT Answer Which Rounds To
© UCLES 2023 Page 5 of 11
AnswerMarks Guidance
QuestionAnswer Marks

AnswerMarks Guidance
6(a)Differentiate using quotient rule M1
(ex +2)8e2x −(4e2x +9)ex
Obtain
AnswerMarks Guidance
(ex +2)2A1 OE
Substitute x=0 in first derivative and attempt evaluationM1
Obtain 11
AnswerMarks
9A1
4

AnswerMarks Guidance
6(b)Equate first derivative to zero and attempt factorisation or
equivalentM1
Solve a three-term quadratic equation in ex to obtain ex =...M1 (2ex +9)(2ex −1)=0.
Obtain x-coordinate ln1 or −ln2
AnswerMarks
2A1
Obtain y-coordinate 4A1
4
AnswerMarks Guidance
QuestionAnswer Marks
Question 6:
6 | Recovery within working is allowed, e.g. a notation error in the working where the following line of working makes the candidate’s intent clear.
PMT
9709/22 Cambridge International AS Level – Mark Scheme February/March 2023
PUBLISHED
Abbreviations
AEF/OE Any Equivalent Form (of answer is equally acceptable) / Or Equivalent
AG Answer Given on the question paper (so extra checking is needed to ensure that the detailed working leading to the result is valid)
CAO Correct Answer Only (emphasising that no ‘follow through’ from a previous error is allowed)
CWO Correct Working Only
ISW Ignore Subsequent Working
SOI Seen Or Implied
SC Special Case (detailing the mark to be given for a specific wrong solution, or a case where some standard marking practice is to be varied in the
light of a particular circumstance)
WWW Without Wrong Working
AWRT Answer Which Rounds To
© UCLES 2023 Page 5 of 11
Question | Answer | Marks | Guidance
--- 6(a) ---
6(a) | Differentiate using quotient rule | M1 | OE
(ex +2)8e2x −(4e2x +9)ex
Obtain
(ex +2)2 | A1 | OE
Substitute x=0 in first derivative and attempt evaluation | M1
Obtain 11
9 | A1
4
--- 6(b) ---
6(b) | Equate first derivative to zero and attempt factorisation or
equivalent | M1
Solve a three-term quadratic equation in ex to obtain ex =... | M1 | (2ex +9)(2ex −1)=0.
Obtain x-coordinate ln1 or −ln2
2 | A1
Obtain y-coordinate 4 | A1
4
Question | Answer | Marks | Guidance
\includegraphics{figure_6}

The diagram shows the curve with equation $y = \frac{4e^{2x} + 9}{e^x + 2}$. The curve has a minimum point $M$ and crosses the $y$-axis at the point $P$.

\begin{enumerate}[label=(\alph*)]
\item Find the exact value of the gradient of the curve at $P$. [4]
\item Find the exact coordinates of $M$. [4]
\end{enumerate}

\hfill \mbox{\textit{CAIE P2 2023 Q6 [8]}}