OCR MEI Further Pure Core 2022 June — Question 5 7 marks

Exam BoardOCR MEI
ModuleFurther Pure Core (Further Pure Core)
Year2022
SessionJune
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicPolar coordinates
TypeArea enclosed by polar curve
DifficultyStandard +0.3 This is a standard Further Maths polar coordinates question involving a cardioid. Part (a) requires sketching a well-known polar curve, and part (b) applies the standard polar area formula ½∫r²dθ with straightforward integration using double angle formulas. While polar coordinates is a Further Maths topic, this is a textbook exercise with no novel problem-solving required, making it slightly easier than average overall.
Spec4.09b Sketch polar curves: r = f(theta)4.09c Area enclosed: by polar curve

5
  1. Sketch the polar curve \(\mathrm { r } = \mathrm { a } ( 1 - \cos \theta ) , 0 \leqslant \theta < 2 \pi\), where \(a\) is a positive constant.
  2. Determine the exact area of the region enclosed by the curve.

Question 5:
AnswerMarks Guidance
5(a) O
A1
AnswerMarks
[2]1.1
1.1symmetrical loop about the initial line
correct shape with cusp at O
AnswerMarks Guidance
5(b) A 2 1 a 2 (1 c o s ) 2 d    =  −
2
0
1 a 2 2 ( 1 2 c o s 1 [1 c o s 2 ] ) d     =  − + +
2 2
0
2𝜋
= 1 𝑎2[3𝜃−4sin𝜃+ 1 sin2𝜃]
4 2 0
3
= 𝜋𝑎2
AnswerMarks
2M1
M1
M1
B1
A1cao
AnswerMarks
[5]1.1a
1.1
3.1a
1.1
AnswerMarks
1.1correct integral and limits, condone missing 𝑑𝜃
limits can be soi by later work
may see ∫ 𝜋 𝑎2(1−cos𝜃)2𝑑𝜃
0
Expanding correctly
substituting for cos2
1
𝑘[3𝜃−4sin𝜃+ sin2𝜃]
2
Question 5:
5 | (a) | O | M1
A1
[2] | 1.1
1.1 | symmetrical loop about the initial line
correct shape with cusp at O
5 | (b) | A 2 1 a 2 (1 c o s ) 2 d    =  −
2
0
1 a 2 2 ( 1 2 c o s 1 [1 c o s 2 ] ) d     =  − + +
2 2
0
2𝜋
= 1 𝑎2[3𝜃−4sin𝜃+ 1 sin2𝜃]
4 2 0
3
= 𝜋𝑎2
2 | M1
M1
M1
B1
A1cao
[5] | 1.1a
1.1
3.1a
1.1
1.1 | correct integral and limits, condone missing 𝑑𝜃
limits can be soi by later work
may see ∫ 𝜋 𝑎2(1−cos𝜃)2𝑑𝜃
0
Expanding correctly
substituting for cos2
1
𝑘[3𝜃−4sin𝜃+ sin2𝜃]
2
5
\begin{enumerate}[label=(\alph*)]
\item Sketch the polar curve $\mathrm { r } = \mathrm { a } ( 1 - \cos \theta ) , 0 \leqslant \theta < 2 \pi$, where $a$ is a positive constant.
\item Determine the exact area of the region enclosed by the curve.
\end{enumerate}

\hfill \mbox{\textit{OCR MEI Further Pure Core 2022 Q5 [7]}}