OCR MEI Paper 2 2019 June — Question 2 4 marks

Exam BoardOCR MEI
ModulePaper 2 (Paper 2)
Year2019
SessionJune
Marks4
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicChain Rule
TypeIntegration using chain rule reversal
DifficultyModerate -0.8 Part (a) is a straightforward application of the chain rule for differentiation. Part (b) is a direct reversal where students recognize the integrand as a multiple of the derivative just found, requiring only adjustment of the constant. This is a standard textbook exercise testing basic understanding of the chain rule and its reversal in integration, with minimal problem-solving required.
Spec1.07r Chain rule: dy/dx = dy/du * du/dx and connected rates1.08a Fundamental theorem of calculus: integration as reverse of differentiation

2 Given that \(y = \left( x ^ { 2 } + 5 \right) ^ { 12 }\),
  1. Find \(\frac { \mathrm { d } y } { \mathrm {~d} x }\).
  2. Hence find \(\int 48 x \left( x ^ { 2 } + 5 \right) ^ { 11 } \mathrm {~d} x\).

Question 2:
Part (a)
AnswerMarks
\(k(x^2+5)^{11}\) seenM1 (AO 1.1a)
\(24x(x^2+5)^{11}\)A1 (AO 1.1)
[2 marks]
Part (b)
AnswerMarks Guidance
\(a(x^2+5)^{12}\)M1 (AO 1.1)
\(2(x^2+5)^{12}(+c)\)A1 (AO 1.1) condone omission of \(+c\)
[2 marks]
## Question 2:

### Part (a)
$k(x^2+5)^{11}$ seen | M1 (AO 1.1a) |
$24x(x^2+5)^{11}$ | A1 (AO 1.1) |
**[2 marks]**

### Part (b)
$a(x^2+5)^{12}$ | M1 (AO 1.1) |
$2(x^2+5)^{12}(+c)$ | A1 (AO 1.1) | condone omission of $+c$ | A1 FT their $kx(x^2+5)^{11}$ from part (a)
**[2 marks]**

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2 Given that $y = \left( x ^ { 2 } + 5 \right) ^ { 12 }$,
\begin{enumerate}[label=(\alph*)]
\item Find $\frac { \mathrm { d } y } { \mathrm {~d} x }$.
\item Hence find $\int 48 x \left( x ^ { 2 } + 5 \right) ^ { 11 } \mathrm {~d} x$.
\end{enumerate}

\hfill \mbox{\textit{OCR MEI Paper 2 2019 Q2 [4]}}