| Exam Board | CAIE |
|---|---|
| Module | P1 (Pure Mathematics 1) |
| Year | 2023 |
| Session | June |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Radians, Arc Length and Sector Area |
| Type | Proving angle relationships |
| Difficulty | Standard +0.3 This is a straightforward application of arc length and sector area formulas with basic trigonometry. Part (a) requires recognizing that the radius OA = x/cos(θ) from the right triangle, then applying arc length = rθ. Part (b) involves subtracting triangle area from sector area using standard formulas. The geometric setup is clear and the methods are routine for P1 level, making this slightly easier than average. |
| Spec | 1.03g Parametric equations: of curves and conversion to cartesian1.05d Radians: arc length s=r*theta and sector area A=1/2 r^2 theta |
| Answer | Marks |
|---|---|
| 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. |
| Answer | Marks | Guidance |
|---|---|---|
| Question | Answer | Marks |
| Answer | Marks |
|---|---|
| 6(a) | 1 OA x |
| Answer | Marks | Guidance |
|---|---|---|
| x2 r2 x2 2rxcos or other valid method. | *B1 | 1 |
| Answer | Marks | Guidance |
|---|---|---|
| OA = 2xcos leading to Arc length = 2xcos | DB1 | AG Complete correct method showing all necessary |
| Answer | Marks |
|---|---|
| 2 | If B0 but www then SCB1 for OA = 2xcos leading to |
| Answer | Marks |
|---|---|
| 6(b) | 1 |
| Answer | Marks | Guidance |
|---|---|---|
| 2 | M1 | OE Using sector formula with a correct OA. Condone |
| Answer | Marks | Guidance |
|---|---|---|
| 2 2 | M1 | Using a correct triangle formula for the correct triangle. |
| Answer | Marks | Guidance |
|---|---|---|
| [Area APB =] Their sector area – their triangle area | M1 | Both expressions must be areas involving terms with x2 and |
| Answer | Marks | Guidance |
|---|---|---|
| 2 | A1 | OE |
| Answer | Marks | Guidance |
|---|---|---|
| Question | Answer | 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
9709/12 Cambridge International AS & A Level – Mark Scheme May/June 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 22
Question | Answer | Marks | Guidance
--- 6(a) ---
6(a) | 1 OA x
OA xcos or or
2 sinπ2 sin
OA2 x2 x2 2x2cosπ2 or
x2 r2 x2 2rxcos or other valid method. | *B1 | 1
Correct expression containing OA, OA or OA2(allow p,
2
a or r for OA) containing only terms with x and but not
just OA2xcos .
Do not condone sinπ2 until missing brackets
recovered or cos(1802) until it becomes cos2 etc.
OA = 2xcos leading to Arc length = 2xcos | DB1 | AG Complete correct method showing all necessary
working. Condone 2xcos .
2 | If B0 but www then SCB1 for OA = 2xcos leading to
Arc length = 2xcos.
--- 6(b) ---
6(b) | 1
2xcos2
Sector area = θ
2 | M1 | OE Using sector formula with a correct OA. Condone
cos2 for cos2 and missing brackets.
1 1
Triangle area = 2xcosxsin OR x2sinπ2
2 2 | M1 | Using a correct triangle formula for the correct triangle.
Condone missing brackets and 180 for π.
[Area APB =] Their sector area – their triangle area | M1 | Both expressions must be areas involving terms with x2 and
only. Condone missing brackets and 180 for π for the
triangle. Condone calling the sector a segment.
1 1
[Area APB =] 2xcos2 x2sinπ2
2 2
1
[ x2(2cos2 sin2) or x2cos(2cos sin)]
2 | A1 | OE
A correct expression. Mark the first unsimplified result of
subtraction and ISW any incorrect ‘simplifications’.
4
Question | Answer | Marks | Guidance
\includegraphics{figure_6}
The diagram shows a sector $OAB$ of a circle with centre $O$. Angle $AOB = \theta$ radians and $OP = AP = x$.
\begin{enumerate}[label=(\alph*)]
\item Show that the arc length $AB$ is $2x\theta \cos \theta$. [2]
\item Find the area of the shaded region $APB$ in terms of $x$ and $\theta$. [4]
\end{enumerate}
\hfill \mbox{\textit{CAIE P1 2023 Q6 [6]}}