AQA FP1 2006 June — Question 9 16 marks

Exam BoardAQA
ModuleFP1 (Further Pure Mathematics 1)
Year2006
SessionJune
Marks16
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCurve Sketching
TypeSimple rational function analysis
DifficultyStandard +0.8 This FP1 question requires multiple techniques: finding asymptotes, algebraic manipulation to derive an inequality condition, interpreting that condition geometrically to locate a stationary point without calculus, and synthesizing all information into a sketch. The non-differentiation constraint in (b)(ii) requires insight that the stationary point occurs at the boundary of the range, making this more challenging than routine curve sketching.
Spec1.02n Sketch curves: simple equations including polynomials1.02t Solve modulus equations: graphically with modulus function

9 A curve \(C\) has equation $$y = \frac { ( x + 1 ) ( x - 3 ) } { x ( x - 2 ) }$$
    1. Write down the coordinates of the points where \(C\) intersects the \(x\)-axis. (2 marks)
    2. Write down the equations of all the asymptotes of \(C\).
    1. Show that, if the line \(y = k\) intersects \(C\), then $$( k - 1 ) ( k - 4 ) \geqslant 0$$
    2. Given that there is only one stationary point on \(C\), find the coordinates of this stationary point.
      (No credit will be given for solutions based on differentiation.)
  1. Sketch the curve \(C\).

Question 9:
Part (a)(i)
AnswerMarks Guidance
WorkingMarks Guidance
Intersections at \((-1, 0)\), \((3, 0)\)B1B1 (2) Allow \(x=-1,\ x=3\)
Part (a)(ii)
AnswerMarks Guidance
WorkingMarks Guidance
Asymptotes \(x=0,\ x=2,\ y=1\)\(\text{B1}\times 3\) (3)
Part (b)(i)
AnswerMarks Guidance
WorkingMarks Guidance
\(y=k \Rightarrow ky^2 - 2kx = x^2 - 2x - 3\)M1A1 M1 for clearing denominator
\(\Rightarrow (k-1)x^2 + (-2k+2)x + 3 = 0\)A1\(\checkmark\) ft numerical error
\(\Delta = 4(k-1)(k-4)\), hence resultm1A1 (5) Convincingly shown AG
Part (b)(ii)
AnswerMarks Guidance
WorkingMarks Guidance
\(y=4\) at SPB1
\(3x^2 - 6x + 3 = 0\), so \(x=1\)M1A1 (3) A0 if other point(s) given
Part (c)
AnswerMarks Guidance
WorkingMarks Guidance
Curve with three branchesB1 Approaching vertical asymptotes
Middle branch correctB1 Coordinates of SP not needed
Other two branches correctB1 (3) 3 asymptotes shown
## Question 9:

### Part (a)(i)
| Working | Marks | Guidance |
|---------|-------|----------|
| Intersections at $(-1, 0)$, $(3, 0)$ | B1B1 (2) | Allow $x=-1,\ x=3$ |

### Part (a)(ii)
| Working | Marks | Guidance |
|---------|-------|----------|
| Asymptotes $x=0,\ x=2,\ y=1$ | $\text{B1}\times 3$ (3) | |

### Part (b)(i)
| Working | Marks | Guidance |
|---------|-------|----------|
| $y=k \Rightarrow ky^2 - 2kx = x^2 - 2x - 3$ | M1A1 | M1 for clearing denominator |
| $\Rightarrow (k-1)x^2 + (-2k+2)x + 3 = 0$ | A1$\checkmark$ | ft numerical error |
| $\Delta = 4(k-1)(k-4)$, hence result | m1A1 (5) | Convincingly shown AG |

### Part (b)(ii)
| Working | Marks | Guidance |
|---------|-------|----------|
| $y=4$ at SP | B1 | |
| $3x^2 - 6x + 3 = 0$, so $x=1$ | M1A1 (3) | A0 if other point(s) given |

### Part (c)
| Working | Marks | Guidance |
|---------|-------|----------|
| Curve with three branches | B1 | Approaching vertical asymptotes |
| Middle branch correct | B1 | Coordinates of SP not needed |
| Other two branches correct | B1 (3) | 3 asymptotes shown |
9 A curve $C$ has equation

$$y = \frac { ( x + 1 ) ( x - 3 ) } { x ( x - 2 ) }$$
\begin{enumerate}[label=(\alph*)]
\item \begin{enumerate}[label=(\roman*)]
\item Write down the coordinates of the points where $C$ intersects the $x$-axis. (2 marks)
\item Write down the equations of all the asymptotes of $C$.
\end{enumerate}\item \begin{enumerate}[label=(\roman*)]
\item Show that, if the line $y = k$ intersects $C$, then

$$( k - 1 ) ( k - 4 ) \geqslant 0$$
\item Given that there is only one stationary point on $C$, find the coordinates of this stationary point.\\
(No credit will be given for solutions based on differentiation.)
\end{enumerate}\item Sketch the curve $C$.
\end{enumerate}

\hfill \mbox{\textit{AQA FP1 2006 Q9 [16]}}