OCR MEI FP1 2008 January — Question 7 11 marks

Exam BoardOCR MEI
ModuleFP1 (Further Pure Mathematics 1)
Year2008
SessionJanuary
Marks11
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicPolynomial Division & Manipulation
TypeSolving Inequalities with Rational Functions
DifficultyStandard +0.3 This is a structured multi-part question on rational functions requiring identification of intercepts, asymptotes, sketching, and solving an inequality. While it involves Further Maths content (FP1), the tasks are largely routine: finding zeros/asymptotes by inspection, analyzing sign changes, and applying standard inequality techniques. The main challenge is careful bookkeeping of sign intervals around multiple asymptotes, but no novel insight is required.
Spec1.02g Inequalities: linear and quadratic in single variable1.02k Simplify rational expressions: factorising, cancelling, algebraic division1.02n Sketch curves: simple equations including polynomials

7 The sketch below shows part of the graph of \(y = \frac { x - 1 } { ( x - 2 ) ( x + 3 ) ( 2 x + 3 ) }\). One section of the graph has been omitted. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{225bff01-f2c4-421f-ac91-c6a0fcb01e6f-3_842_1198_477_552} \captionsetup{labelformat=empty} \caption{Fig. 7}
\end{figure}
  1. Find the coordinates of the points where the curve crosses the axes.
  2. Write down the equations of the three vertical asymptotes and the one horizontal asymptote.
  3. Copy the sketch and draw in the missing section.
  4. Solve the inequality \(\frac { x - 1 } { ( x - 2 ) ( x + 3 ) ( 2 x + 3 ) } \geqslant 0\).

Question 7(i):
AnswerMarks Guidance
Answer/WorkingMark Guidance
\((1,\ 0)\) and \(\left(0,\ \frac{1}{18}\right)\)B1, B1 [2]
Question 7(ii):
AnswerMarks Guidance
Answer/WorkingMark Guidance
\(x=2,\ x=-3,\ x=-\frac{3}{2},\ y=0\)B4 [4] Minus 1 for each error
Question 7(iii):
AnswerMarks Guidance
Answer/WorkingMark Guidance
Sketch of curveB1 Correct approaches to vertical asymptotes
B1 [2]Through clearly marked \((1,0)\) and \(\left(0,\frac{1}{18}\right)\)
Question 7(iv):
AnswerMarks Guidance
Answer/WorkingMark Guidance
\(x < -3,\ x > 2\)B1
\(-\frac{3}{2} < x \leq 1\)B2 [3] B1 for \(-\frac{3}{2} < x < 1\), or \(-\frac{3}{2} \leq x \leq 1\)
# Question 7(i):

| Answer/Working | Mark | Guidance |
|---|---|---|
| $(1,\ 0)$ and $\left(0,\ \frac{1}{18}\right)$ | B1, B1 **[2]** | |

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# Question 7(ii):

| Answer/Working | Mark | Guidance |
|---|---|---|
| $x=2,\ x=-3,\ x=-\frac{3}{2},\ y=0$ | B4 **[4]** | Minus 1 for each error |

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# Question 7(iii):

| Answer/Working | Mark | Guidance |
|---|---|---|
| Sketch of curve | B1 | Correct approaches to vertical asymptotes |
| | B1 **[2]** | Through clearly marked $(1,0)$ and $\left(0,\frac{1}{18}\right)$ |

---

# Question 7(iv):

| Answer/Working | Mark | Guidance |
|---|---|---|
| $x < -3,\ x > 2$ | B1 | |
| $-\frac{3}{2} < x \leq 1$ | B2 **[3]** | B1 for $-\frac{3}{2} < x < 1$, or $-\frac{3}{2} \leq x \leq 1$ |

---
7 The sketch below shows part of the graph of $y = \frac { x - 1 } { ( x - 2 ) ( x + 3 ) ( 2 x + 3 ) }$. One section of the graph has been omitted.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{225bff01-f2c4-421f-ac91-c6a0fcb01e6f-3_842_1198_477_552}
\captionsetup{labelformat=empty}
\caption{Fig. 7}
\end{center}
\end{figure}

(i) Find the coordinates of the points where the curve crosses the axes.\\
(ii) Write down the equations of the three vertical asymptotes and the one horizontal asymptote.\\
(iii) Copy the sketch and draw in the missing section.\\
(iv) Solve the inequality $\frac { x - 1 } { ( x - 2 ) ( x + 3 ) ( 2 x + 3 ) } \geqslant 0$.

\hfill \mbox{\textit{OCR MEI FP1 2008 Q7 [11]}}