OCR MEI FP1 2010 January — Question 7 12 marks

Exam BoardOCR MEI
ModuleFP1 (Further Pure Mathematics 1)
Year2010
SessionJanuary
Marks12
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicPartial Fractions
TypeRational curve sketching with asymptotes and inequalities
DifficultyStandard +0.3 This is a standard Further Pure 1 question on rational functions requiring identification of asymptotes (straightforward from denominator zeros and degree comparison), basic limit behavior analysis, curve sketching, and solving a rational inequality. While it's a multi-part question worth several marks, each component follows routine procedures taught in FP1 with no novel problem-solving required. It's slightly above average difficulty due to being Further Maths content and requiring careful sign analysis for part (iv), but remains a textbook-style exercise.
Spec1.02g Inequalities: linear and quadratic in single variable1.02n Sketch curves: simple equations including polynomials

7 A curve has equation \(y = \frac { 5 x - 9 } { ( 2 x - 3 ) ( 2 x + 7 ) }\).
  1. Write down the equations of the two vertical asymptotes and the one horizontal asymptote.
  2. Describe the behaviour of the curve for large positive and large negative values of \(x\), justifying your answers.
  3. Sketch the curve.
  4. Solve the inequality \(\frac { 5 x - 9 } { ( 2 x - 3 ) ( 2 x + 7 ) } \leqslant 0\).

Question 7:
Part (i):
AnswerMarks Guidance
AnswerMark Guidance
\(x = -\frac{7}{2}\), \(x = \frac{3}{2}\), \(y = 0\)B1, B1, B1 [3]
Part (ii):
AnswerMarks Guidance
AnswerMark Guidance
Large positive \(x\), \(y \to 0^+\) (e.g. \(x=100\))B1, B1
Large negative \(x\), \(y \to 0^-\) (e.g. \(x=-100\))M1 [3] Evidence of method
Part (iii):
AnswerMarks Guidance
AnswerMark Guidance
Intercepts correct and labelledB1
LH and central branches correctB1
RH branch correct, with clear maximumB1 [3]
Part (iv):
AnswerMarks Guidance
AnswerMark Guidance
\(x < -\frac{7}{2}\)B1
or \(\frac{3}{2} < x \leq \frac{9}{5}\)B2 [3] Award B1 if only error relates to inclusive/exclusive inequalities
# Question 7:

**Part (i):**

| Answer | Mark | Guidance |
|--------|------|----------|
| $x = -\frac{7}{2}$, $x = \frac{3}{2}$, $y = 0$ | B1, B1, B1 **[3]** | |

**Part (ii):**

| Answer | Mark | Guidance |
|--------|------|----------|
| Large positive $x$, $y \to 0^+$ (e.g. $x=100$) | B1, B1 | |
| Large negative $x$, $y \to 0^-$ (e.g. $x=-100$) | M1 **[3]** | Evidence of method |

**Part (iii):**

| Answer | Mark | Guidance |
|--------|------|----------|
| Intercepts correct and labelled | B1 | |
| LH and central branches correct | B1 | |
| RH branch correct, with clear maximum | B1 **[3]** | |

**Part (iv):**

| Answer | Mark | Guidance |
|--------|------|----------|
| $x < -\frac{7}{2}$ | B1 | |
| or $\frac{3}{2} < x \leq \frac{9}{5}$ | B2 **[3]** | Award B1 if only error relates to inclusive/exclusive inequalities |

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7 A curve has equation $y = \frac { 5 x - 9 } { ( 2 x - 3 ) ( 2 x + 7 ) }$.\\
(i) Write down the equations of the two vertical asymptotes and the one horizontal asymptote.\\
(ii) Describe the behaviour of the curve for large positive and large negative values of $x$, justifying your answers.\\
(iii) Sketch the curve.\\
(iv) Solve the inequality $\frac { 5 x - 9 } { ( 2 x - 3 ) ( 2 x + 7 ) } \leqslant 0$.

\hfill \mbox{\textit{OCR MEI FP1 2010 Q7 [12]}}