OCR MEI FP1 2008 June — Question 8 12 marks

Exam BoardOCR MEI
ModuleFP1 (Further Pure Mathematics 1)
Year2008
SessionJune
Marks12
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicPolynomial Division & Manipulation
TypeSolving Inequalities with Rational Functions
DifficultyStandard +0.3 This is a standard FP1 rational function question requiring identification of asymptotes, behavior analysis, sketching, and solving an inequality. While it involves multiple parts, each step follows routine procedures: vertical asymptotes from denominators, horizontal from degree comparison, sign analysis for the inequality. The techniques are well-practiced in FP1 with no novel insight required, making it slightly easier than average.
Spec1.02g Inequalities: linear and quadratic in single variable1.02n Sketch curves: simple equations including polynomials1.02y Partial fractions: decompose rational functions

8 A curve has equation \(y = \frac { 2 x ^ { 2 } } { ( x - 3 ) ( x + 2 ) }\).
  1. Write down the equations of the three asymptotes.
  2. Determine whether the curve approaches the horizontal asymptote from above or below for
    (A) large positive values of \(x\),
    (B) large negative values of \(x\).
  3. Sketch the curve.
  4. Solve the inequality \(\frac { 2 x ^ { 2 } } { ( x - 3 ) ( x + 2 ) } < 0\).

Question 8:
Question 8(i):
AnswerMarks
\(x = 3\), \(x = -2\), \(y = 2\)B1, B1, B1 [3]
Question 8(ii) & 8(iii):
AnswerMarks Guidance
Large positive \(x\), \(y \rightarrow 2^+\) (e.g. consider \(x = 100\)); Large negative \(x\), \(y \rightarrow 2^-\) (e.g. consider \(x = -100\))M1, B1, B1 [3] Evidence of method required
Curve: Central and RH branches correct; Asymptotes correct and labelled; LH branch correct, with clear minimumB1, B1, B1 [3]
Question 8(iv):
AnswerMarks Guidance
\(-2 < x < 3\), \(x \neq 0\)B2, B1 [3] B2 max if any inclusive inequalities appear; B3 for \(-2 < x < 0\) and \(0 < x < 3\)
# Question 8:

## Question 8(i):
| $x = 3$, $x = -2$, $y = 2$ | B1, B1, B1 [3] | |

## Question 8(ii) & 8(iii):
| Large positive $x$, $y \rightarrow 2^+$ (e.g. consider $x = 100$); Large negative $x$, $y \rightarrow 2^-$ (e.g. consider $x = -100$) | M1, B1, B1 [3] | Evidence of method required |
| Curve: Central and RH branches correct; Asymptotes correct and labelled; LH branch correct, with clear minimum | B1, B1, B1 [3] | |

## Question 8(iv):
| $-2 < x < 3$, $x \neq 0$ | B2, B1 [3] | B2 max if any inclusive inequalities appear; B3 for $-2 < x < 0$ and $0 < x < 3$ |

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8 A curve has equation $y = \frac { 2 x ^ { 2 } } { ( x - 3 ) ( x + 2 ) }$.
\begin{enumerate}[label=(\roman*)]
\item Write down the equations of the three asymptotes.
\item Determine whether the curve approaches the horizontal asymptote from above or below for\\
(A) large positive values of $x$,\\
(B) large negative values of $x$.
\item Sketch the curve.
\item Solve the inequality $\frac { 2 x ^ { 2 } } { ( x - 3 ) ( x + 2 ) } < 0$.
\end{enumerate}

\hfill \mbox{\textit{OCR MEI FP1 2008 Q8 [12]}}