Edexcel C1 2011 January — Question 5 7 marks

Exam BoardEdexcel
ModuleC1 (Core Mathematics 1)
Year2011
SessionJanuary
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicFunction Transformations
TypeComposite transformation sketch
DifficultyModerate -0.3 This is a straightforward C1 transformation question requiring a horizontal translation of +1. Students must sketch the transformed curve, identify new asymptotes (x=3, y=1), and find axis intercepts by substituting x=0 and y=0. While it involves multiple steps, each is routine application of standard transformation rules with no novel problem-solving required.
Spec1.02v Inverse and composite functions: graphs and conditions for existence1.02w Graph transformations: simple transformations of f(x)

5. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{95e11fd7-765c-477d-800b-7574bc1af81f-06_640_1063_322_438} \captionsetup{labelformat=empty} \caption{Figure 1}
\end{figure} Figure 1 shows a sketch of the curve with equation \(y = \mathrm { f } ( x )\) where $$\mathrm { f } ( x ) = \frac { x } { x - 2 } , \quad x \neq 2$$ The curve passes through the origin and has two asymptotes, with equations \(y = 1\) and \(x = 2\), as shown in Figure 1.
  1. In the space below, sketch the curve with equation \(y = \mathrm { f } ( x - 1 )\) and state the equations of the asymptotes of this curve.
  2. Find the coordinates of the points where the curve with equation \(y = \mathrm { f } ( x - 1 )\) crosses the coordinate axes.

Question 5:
Part (a):
AnswerMarks
Correct shape with a single crossing of each axisB1
\(y = 1\) labelled or statedB1
\(x = 3\) labelled or statedB1
(3 marks total)
Part (b):
AnswerMarks Guidance
Horizontal translation so crosses the \(x\)-axis at \((1, 0)\)B1 For point \((1,0)\) identified; may be marked on sketch as 1 on \(x\)-axis; accept \(x=1\)
New equation is \((y =)\ \dfrac{x \pm 1}{(x \pm 1)-2}\)M1 For attempt at new equation with either numerator or denominator correct
When \(x = 0\), \(y =\)M1 For setting \(x=0\) in their new equation and solving as far as \(y = \ldots\)
\(= \dfrac{1}{3}\)A1 For \(\frac{1}{3}\) or exact equivalent; must see \(y = \frac{1}{3}\) or \((0, \frac{1}{3})\) or point marked on \(y\)-axis
(4 marks total)
## Question 5:

### Part (a):
| Correct shape with a single crossing of each axis | B1 | |
| $y = 1$ labelled or stated | B1 | |
| $x = 3$ labelled or stated | B1 | |
|(3 marks total)|||

### Part (b):
| Horizontal translation so crosses the $x$-axis at $(1, 0)$ | B1 | For point $(1,0)$ identified; may be marked on sketch as 1 on $x$-axis; accept $x=1$ |
| New equation is $(y =)\ \dfrac{x \pm 1}{(x \pm 1)-2}$ | M1 | For attempt at new equation with either numerator or denominator correct |
| When $x = 0$, $y =$ | M1 | For setting $x=0$ in their new equation and solving as far as $y = \ldots$ |
| $= \dfrac{1}{3}$ | A1 | For $\frac{1}{3}$ or exact equivalent; must see $y = \frac{1}{3}$ or $(0, \frac{1}{3})$ or point marked on $y$-axis |
|(4 marks total)|||

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5.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{95e11fd7-765c-477d-800b-7574bc1af81f-06_640_1063_322_438}
\captionsetup{labelformat=empty}
\caption{Figure 1}
\end{center}
\end{figure}

Figure 1 shows a sketch of the curve with equation $y = \mathrm { f } ( x )$ where

$$\mathrm { f } ( x ) = \frac { x } { x - 2 } , \quad x \neq 2$$

The curve passes through the origin and has two asymptotes, with equations $y = 1$ and $x = 2$, as shown in Figure 1.
\begin{enumerate}[label=(\alph*)]
\item In the space below, sketch the curve with equation $y = \mathrm { f } ( x - 1 )$ and state the equations of the asymptotes of this curve.
\item Find the coordinates of the points where the curve with equation $y = \mathrm { f } ( x - 1 )$ crosses the coordinate axes.
\end{enumerate}

\hfill \mbox{\textit{Edexcel C1 2011 Q5 [7]}}