CAIE P1 2010 November — Question 8 8 marks

Exam BoardCAIE
ModuleP1 (Pure Mathematics 1)
Year2010
SessionNovember
Marks8
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCircles
TypeArea of region bounded by circle and line
DifficultyStandard +0.8 This question requires understanding of rhombus properties, sector areas, and coordinate geometry with radians. Students must find two sector areas, subtract them, work with non-standard angles (1.2 radians), and apply the cosine rule or similar techniques to find PQ. The multi-step nature and integration of several topics (geometry, trigonometry, circles) makes this moderately challenging, though the techniques themselves are standard A-level material.
Spec1.05d Radians: arc length s=r*theta and sector area A=1/2 r^2 theta

8 \includegraphics[max width=\textwidth, alt={}, center]{32a57386-2696-4fda-a3cb-ca0c5c3be432-3_600_883_1731_630} The diagram shows a rhombus \(A B C D\). Points \(P\) and \(Q\) lie on the diagonal \(A C\) such that \(B P D\) is an arc of a circle with centre \(C\) and \(B Q D\) is an arc of a circle with centre \(A\). Each side of the rhombus has length 5 cm and angle \(B A D = 1.2\) radians.
  1. Find the area of the shaded region \(B P D Q\).
  2. Find the length of \(P Q\).

Question 8:
Part (i):
AnswerMarks Guidance
Answer/WorkingMarks Guidance
\(\frac{1}{2} \times 5^2 \times 1.2\)B1
\(\frac{1}{2} \times 5^2 \times \sin 1.2\)B1
\(2\left[\frac{1}{2} \times 5^2 \times 1.2 - \frac{1}{2} \times 5^2 \times \sin 1.2\right]\)M1 Subtraction and multiplication by 2
\(6.70\)A1 Accept 6.7 or anything rounding to 6.70
[4]
Part (ii):
AnswerMarks Guidance
Answer/WorkingMarks Guidance
\(5\cos 0.6\)M1
\(5 - \text{"} 5\cos 0.6\text{"}\)M1 Subtraction from 5
\(10(1 - \cos 0.6)\)M1 Multiplication by 2
\(1.75\)A1
[4]
## Question 8:

### Part (i):
| Answer/Working | Marks | Guidance |
|---|---|---|
| $\frac{1}{2} \times 5^2 \times 1.2$ | B1 | |
| $\frac{1}{2} \times 5^2 \times \sin 1.2$ | B1 | |
| $2\left[\frac{1}{2} \times 5^2 \times 1.2 - \frac{1}{2} \times 5^2 \times \sin 1.2\right]$ | M1 | Subtraction and multiplication by 2 |
| $6.70$ | A1 | Accept 6.7 or anything rounding to 6.70 |
| **[4]** | | |

### Part (ii):
| Answer/Working | Marks | Guidance |
|---|---|---|
| $5\cos 0.6$ | M1 | |
| $5 - \text{"} 5\cos 0.6\text{"}$ | M1 | Subtraction from 5 |
| $10(1 - \cos 0.6)$ | M1 | Multiplication by 2 |
| $1.75$ | A1 | |
| **[4]** | | |

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8\\
\includegraphics[max width=\textwidth, alt={}, center]{32a57386-2696-4fda-a3cb-ca0c5c3be432-3_600_883_1731_630}

The diagram shows a rhombus $A B C D$. Points $P$ and $Q$ lie on the diagonal $A C$ such that $B P D$ is an arc of a circle with centre $C$ and $B Q D$ is an arc of a circle with centre $A$. Each side of the rhombus has length 5 cm and angle $B A D = 1.2$ radians.\\
(i) Find the area of the shaded region $B P D Q$.\\
(ii) Find the length of $P Q$.

\hfill \mbox{\textit{CAIE P1 2010 Q8 [8]}}