OCR MEI Further Pure Core 2019 June — Question 4 3 marks

Exam BoardOCR MEI
ModuleFurther Pure Core (Further Pure Core)
Year2019
SessionJune
Marks3
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicVolumes of Revolution
TypeVolume with trigonometric functions
DifficultyChallenging +1.2 This is a straightforward volumes of revolution question requiring integration of sec²(x/2), which is a standard result. While it involves trigonometric functions and requires careful substitution (u = x/2), the method is routine for Further Maths students and the integration is a known formula. The 'show detailed reasoning' requirement and exact form answer add minor complexity but this remains a standard textbook exercise.
Spec1.05h Reciprocal trig functions: sec, cosec, cot definitions and graphs4.08d Volumes of revolution: about x and y axes

4 In this question you must show detailed reasoning. Fig. 4 shows the region bounded by the curve \(y = \sec \frac { 1 } { 2 } x\), the \(x\)-axis, the \(y\)-axis and the line \(x = \frac { 1 } { 2 } \pi\). \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{01a574f1-f6f6-40f5-baa5-535c36269731-2_501_670_1329_242} \captionsetup{labelformat=empty} \caption{Fig. 4}
\end{figure} This region is rotated through \(2 \pi\) radians about the \(x\)-axis.
Find, in exact form, the volume of the solid of revolution generated.

Question 4:
AnswerMarks
4DR
1
V 2sec2 xdx
0 2
 1 2
 2tan x
 
 2 
0
AnswerMarks
= (2tan ¼ π  0) = 2B1
B1
B1cao
AnswerMarks
[3]1.1b
1.1b
AnswerMarks
1.1bcorrect integral and limits
1
2tan x
2
AnswerMarks
unsupported B0condone π missing
Question 4:
4 | DR

1
V 2sec2 xdx
0 2

 1 2
 2tan x
 
 2 
0
= (2tan ¼ π  0) = 2 | B1
B1
B1cao
[3] | 1.1b
1.1b
1.1b | correct integral and limits
1
2tan x
2
unsupported B0 | condone π missing
4 In this question you must show detailed reasoning.
Fig. 4 shows the region bounded by the curve $y = \sec \frac { 1 } { 2 } x$, the $x$-axis, the $y$-axis and the line $x = \frac { 1 } { 2 } \pi$.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{01a574f1-f6f6-40f5-baa5-535c36269731-2_501_670_1329_242}
\captionsetup{labelformat=empty}
\caption{Fig. 4}
\end{center}
\end{figure}

This region is rotated through $2 \pi$ radians about the $x$-axis.\\
Find, in exact form, the volume of the solid of revolution generated.

\hfill \mbox{\textit{OCR MEI Further Pure Core 2019 Q4 [3]}}