AQA FP1 2016 June — Question 9 11 marks

Exam BoardAQA
ModuleFP1 (Further Pure Mathematics 1)
Year2016
SessionJune
Marks11
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCurve Sketching
TypeSolve f(x) > g(x) using sketch
DifficultyStandard +0.3 This is a standard FP1 rational function question with routine steps: identifying asymptotes from denominator zeros, solving a cubic that factors nicely (x-1 is clearly a common factor), sketching with given information, and reading off an inequality from the sketch. While it requires multiple techniques, each step follows predictable patterns with no novel insight needed, making it slightly easier than average.
Spec1.02g Inequalities: linear and quadratic in single variable1.02k Simplify rational expressions: factorising, cancelling, algebraic division1.02n Sketch curves: simple equations including polynomials

A curve \(C\) has equation \(y = \frac{x - 1}{(x - 2)(2x - 1)}\). The line \(L\) has equation \(y = \frac{1}{2}(x - 1)\).
  1. Write down the equations of the asymptotes of \(C\). [2 marks]
  2. By forming and solving a suitable cubic equation, find the \(x\)-coordinates of the points of intersection of \(L\) and \(C\). [3 marks]
  3. Given that \(C\) has no stationary points, sketch \(C\) and \(L\) on the same axes. [3 marks]
  4. Hence solve the inequality \(\frac{x - 1}{(x - 2)(2x - 1)} \geqslant \frac{1}{2}(x - 1)\). [3 marks]

AnswerMarks Guidance
(a) \(x = 2\); \(x = 0.5\); \(y = 0\)B2,1,0 OE , B1 for two correct equations and no more than one incorrect equation
Total for (a): 2 marks
AnswerMarks Guidance
(b) \(\frac{1}{2}(x-1) = \frac{x-1}{(x-2)(2x-1)}\)M1 Correct elimination of \(y\)
\(\frac{1}{2}(x-1)(x-2)(2x-1) = x-1\)A1 Any correct cubic
\((x-1)(x-2)(2x-1) = 2(x-1)\)
\((x-1)[2x^2-5x] = 0\)A1 From a relevant factorised form or from \(2x^3 - 7x^2 + 5x = 0\) obtained from correct working
\(x = 0\), \(x = 1\), \(x = 2.5\)A1 From a relevant factorised form or from \(2x^3 - 7x^2 + 5x = 0\) obtained from correct working
Total for (b): 3 marks
AnswerMarks
(c) C: 3-branch curve, no parabolas, no branch having positive slopes. Condone slight deviations at the two horizontal extremes.B1
C: correct curve with correct asymptotic behaviour with correct asymptotes seen/impliedB1
L: correct 'line', intersecting a 3-branch curve at 3 points, two of which are on the coordinate axesB1
Total for (c): 3 marks
AnswerMarks Guidance
(d) \(x \le 0\), \(0.5 < x \le 1\), \(2 < x \le 2.5\)M1 Three inequalities consistent with the \(c\)'s 3-branch curve \(C\) and line \(L\) with positive slope drawn in part (c), ft three values of \(x\) obtained in (b) used with correct values for vertical asymptotes, condoning \(<\) for \(\le\) and vice versa
A2,1A2 all three inequalities correct. A1 if only error is either one or both '<' replaced by '\(\le\)' or one '\(\le\)' replaced by '<'
Total for (d): 3 marks
Overall Total: 11 marks
**(a)** $x = 2$; $x = 0.5$; $y = 0$ | B2,1,0 | OE , B1 for two correct equations and no more than one incorrect equation

**Total for (a): 2 marks**

**(b)** $\frac{1}{2}(x-1) = \frac{x-1}{(x-2)(2x-1)}$ | M1 | Correct elimination of $y$

$\frac{1}{2}(x-1)(x-2)(2x-1) = x-1$ | A1 | Any correct cubic

$(x-1)(x-2)(2x-1) = 2(x-1)$ | | 

$(x-1)[2x^2-5x] = 0$ | A1 | From a relevant factorised form or from $2x^3 - 7x^2 + 5x = 0$ obtained from correct working

$x = 0$, $x = 1$, $x = 2.5$ | A1 | From a relevant factorised form or from $2x^3 - 7x^2 + 5x = 0$ obtained from correct working

**Total for (b): 3 marks**

**(c)** C: 3-branch curve, no parabolas, no branch having positive slopes. Condone slight deviations at the two horizontal extremes. | B1 | 

C: correct curve with correct asymptotic behaviour with correct asymptotes seen/implied | B1 | 

L: correct 'line', intersecting a 3-branch curve at 3 points, two of which are on the coordinate axes | B1 | 

**Total for (c): 3 marks**

**(d)** $x \le 0$, $0.5 < x \le 1$, $2 < x \le 2.5$ | M1 | Three inequalities consistent with the $c$'s 3-branch curve $C$ and line $L$ with positive slope drawn in part (c), ft three values of $x$ obtained in (b) used with correct values for vertical asymptotes, condoning $<$ for $\le$ and vice versa

| A2,1 | A2 all three inequalities correct. A1 if only error is either one or both '<' replaced by '$\le$' or one '$\le$' replaced by '<'

**Total for (d): 3 marks**

**Overall Total: 11 marks**
A curve $C$ has equation $y = \frac{x - 1}{(x - 2)(2x - 1)}$.

The line $L$ has equation $y = \frac{1}{2}(x - 1)$.

\begin{enumerate}[label=(\alph*)]
\item Write down the equations of the asymptotes of $C$.
[2 marks]

\item By forming and solving a suitable cubic equation, find the $x$-coordinates of the points of intersection of $L$ and $C$.
[3 marks]

\item Given that $C$ has no stationary points, sketch $C$ and $L$ on the same axes.
[3 marks]

\item Hence solve the inequality $\frac{x - 1}{(x - 2)(2x - 1)} \geqslant \frac{1}{2}(x - 1)$.
[3 marks]
\end{enumerate}

\hfill \mbox{\textit{AQA FP1 2016 Q9 [11]}}