AQA FP2 2007 June — Question 4 7 marks

Exam BoardAQA
ModuleFP2 (Further Pure Mathematics 2)
Year2007
SessionJune
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicIntegration by Parts
TypeIntegration involving inverse trig
DifficultyStandard +0.3 This is a straightforward integration by parts question with inverse trig. Part (a) is routine product rule differentiation. Part (b) directly uses the result from (a) to integrate by parts with clear limits and standard simplification. While inverse trig integration is FP2 content, the question is highly scaffolded and follows a standard template, making it slightly easier than average overall.
Spec1.07q Product and quotient rules: differentiation1.08i Integration by parts

4
  1. Differentiate \(x \tan ^ { - 1 } x\) with respect to \(x\).
  2. Show that $$\int _ { 0 } ^ { 1 } \tan ^ { - 1 } x \mathrm {~d} x = \frac { \pi } { 4 } - \ln \sqrt { 2 }$$ (5 marks)

Question 4:
Part (a)
AnswerMarks Guidance
WorkingMarks Guidance
\(\frac{x}{1+x^2} + \tan^{-1}x\)B1B1
Part (b)
AnswerMarks Guidance
WorkingMarks Guidance
\(\int_0^1 \tan^{-1}x\,dx = \left[x\tan^{-1}x\right]_0^1 - \int_0^1 \frac{x\,dx}{1+x^2}\)M1 either use of part (a) or integration by parts. Allow if sign error
\(\int \frac{x\,dx}{1+x^2} = \frac{1}{2}\ln(1+x^2)\)M1A1F ft on \(\int\frac{x}{1-x^2}dx\)
\(I = 1\cdot\tan^{-1}1 - \frac{1}{2}\ln 2\)M1
\(= \frac{\pi}{4} - \ln\sqrt{2}\)A1 AG
## Question 4:

### Part (a)
| Working | Marks | Guidance |
|---------|-------|----------|
| $\frac{x}{1+x^2} + \tan^{-1}x$ | B1B1 | |

### Part (b)
| Working | Marks | Guidance |
|---------|-------|----------|
| $\int_0^1 \tan^{-1}x\,dx = \left[x\tan^{-1}x\right]_0^1 - \int_0^1 \frac{x\,dx}{1+x^2}$ | M1 | either use of part (a) or integration by parts. Allow if sign error |
| $\int \frac{x\,dx}{1+x^2} = \frac{1}{2}\ln(1+x^2)$ | M1A1F | ft on $\int\frac{x}{1-x^2}dx$ |
| $I = 1\cdot\tan^{-1}1 - \frac{1}{2}\ln 2$ | M1 | |
| $= \frac{\pi}{4} - \ln\sqrt{2}$ | A1 | AG |

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4
\begin{enumerate}[label=(\alph*)]
\item Differentiate $x \tan ^ { - 1 } x$ with respect to $x$.
\item Show that

$$\int _ { 0 } ^ { 1 } \tan ^ { - 1 } x \mathrm {~d} x = \frac { \pi } { 4 } - \ln \sqrt { 2 }$$

(5 marks)
\end{enumerate}

\hfill \mbox{\textit{AQA FP2 2007 Q4 [7]}}