AQA FP1 2007 January — Question 6 10 marks

Exam BoardAQA
ModuleFP1 (Further Pure Mathematics 1)
Year2007
SessionJanuary
Marks10
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicSequences and series, recurrence and convergence
TypeStandard summation formulae application
DifficultyModerate -0.5 This is a routine Further Maths question using standard summation techniques. Part (a)(i) is trivial algebra, part (a)(ii) requires applying standard Σr and Σr² formulae (core FP1 content), and part (b) is straightforward substitution. While it's multi-step, it follows a completely standard template with no problem-solving insight required, making it easier than average even for Further Maths.
Spec4.06a Summation formulae: sum of r, r^2, r^3

6
    1. Expand \(( 2 r - 1 ) ^ { 2 }\).
    2. Hence show that $$\sum _ { r = 1 } ^ { n } ( 2 r - 1 ) ^ { 2 } = \frac { 1 } { 3 } n \left( 4 n ^ { 2 } - 1 \right)$$
  1. Hence find the sum of the squares of the odd numbers between 100 and 200 .

Part (a)(i)
AnswerMarks Guidance
\((2r - 1)^2 = 4r^2 - 4r + 1\)B1 1 mark
Part (a)(ii)
AnswerMarks Guidance
\(\sum (2r - 1)^2 = 4\sum r^2 - 4\sum r + \sum 1\)M1
\(\ldots = \frac{4}{3}n^3 - \frac{4}{3}n + \sum 1\)m1A1
\(\sum 1 = n\)B1
Result convincingly shownA1 5 marks
Part (b)
AnswerMarks Guidance
Sum \(= f(100) - f(50)\)M1A1
\(\ldots = 1166 650\)A2 4 marks
Total for Question 6: 10 marks
### Part (a)(i)
$(2r - 1)^2 = 4r^2 - 4r + 1$ | B1 | 1 mark |

### Part (a)(ii)
$\sum (2r - 1)^2 = 4\sum r^2 - 4\sum r + \sum 1$ | M1 | |
$\ldots = \frac{4}{3}n^3 - \frac{4}{3}n + \sum 1$ | m1A1 | |
$\sum 1 = n$ | B1 | |
Result convincingly shown | A1 | 5 marks | AG

### Part (b)
Sum $= f(100) - f(50)$ | M1A1 | |
$\ldots = 1166 650$ | A2 | 4 marks | SC f(100) - f(51) = 1 156 449; 3/4

### **Total for Question 6: 10 marks**

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6
\begin{enumerate}[label=(\alph*)]
\item \begin{enumerate}[label=(\roman*)]
\item Expand $( 2 r - 1 ) ^ { 2 }$.
\item Hence show that

$$\sum _ { r = 1 } ^ { n } ( 2 r - 1 ) ^ { 2 } = \frac { 1 } { 3 } n \left( 4 n ^ { 2 } - 1 \right)$$
\end{enumerate}\item Hence find the sum of the squares of the odd numbers between 100 and 200 .
\end{enumerate}

\hfill \mbox{\textit{AQA FP1 2007 Q6 [10]}}