AQA FP1 2010 January — Question 7 9 marks

Exam BoardAQA
ModuleFP1 (Further Pure Mathematics 1)
Year2010
SessionJanuary
Marks9
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCurve Sketching
TypeSketch rational with linear numerator
DifficultyStandard +0.3 This is a straightforward FP1 question combining routine curve sketching of a simple rational function with standard interval bisection. Part (a) requires identifying asymptotes and sketching a basic reciprocal square function—both standard techniques. Part (b) involves verifying a root lies in an interval by sign change and applying the mechanical interval bisection algorithm twice. While it spans multiple techniques, each component is routine and well-practiced at this level, making it slightly easier than average overall.
Spec1.02n Sketch curves: simple equations including polynomials1.02o Sketch reciprocal curves: y=a/x and y=a/x^21.09a Sign change methods: locate roots

7 A curve \(C\) has equation \(y = \frac { 1 } { ( x - 2 ) ^ { 2 } }\).
    1. Write down the equations of the asymptotes of the curve \(C\).
    2. Sketch the curve \(C\).
  1. The line \(y = x - 3\) intersects the curve \(C\) at a point which has \(x\)-coordinate \(\alpha\).
    1. Show that \(\alpha\) lies within the interval \(3 < x < 4\).
    2. Starting from the interval \(3 < x < 4\), use interval bisection twice to obtain an interval of width 0.25 within which \(\alpha\) must lie.

AnswerMarks Guidance
7(a)(i)Asymptotes \(x = 2, y = 0\) B1B1
7(a)(ii)One correct branch B1
Both branches correctB1 2 marks
7(b)(i)\(f(3) = -1, f(4) = 3\) B1
Sign change, so \(\alpha\) between 3 and 4E1 2 marks
7(b)(ii)\(f(3.5)\) considered first M1
\(f(3.5) > 0\) so \(3 < \alpha < 3.5\)A1 Some numerical value(s) needed
\(f(3.25) < 0\) so \(3.25 < \alpha < 3.5\)A1 3 marks
Total for Q79 marks
7(a)(i) | Asymptotes $x = 2, y = 0$ | B1B1 | 2 marks |

7(a)(ii) | One correct branch | B1 | |
| Both branches correct | B1 | 2 marks | no extra branches; $x = 2$ shown |

7(b)(i) | $f(3) = -1, f(4) = 3$ | B1 | where $f(x) = (x-3)(x - 2)^2 - 1$; OE |
| Sign change, so $\alpha$ between 3 and 4 | E1 | 2 marks |

7(b)(ii) | $f(3.5)$ considered first | M1 | OE but must consider $x = 3.5$ |
| $f(3.5) > 0$ so $3 < \alpha < 3.5$ | A1 | Some numerical value(s) needed |
| $f(3.25) < 0$ so $3.25 < \alpha < 3.5$ | A1 | 3 marks | Condone absence of values here |

| **Total for Q7** | **9 marks** |

---
7 A curve $C$ has equation $y = \frac { 1 } { ( x - 2 ) ^ { 2 } }$.
\begin{enumerate}[label=(\alph*)]
\item \begin{enumerate}[label=(\roman*)]
\item Write down the equations of the asymptotes of the curve $C$.
\item Sketch the curve $C$.
\end{enumerate}\item The line $y = x - 3$ intersects the curve $C$ at a point which has $x$-coordinate $\alpha$.
\begin{enumerate}[label=(\roman*)]
\item Show that $\alpha$ lies within the interval $3 < x < 4$.
\item Starting from the interval $3 < x < 4$, use interval bisection twice to obtain an interval of width 0.25 within which $\alpha$ must lie.
\end{enumerate}\end{enumerate}

\hfill \mbox{\textit{AQA FP1 2010 Q7 [9]}}