Edexcel C1 2008 January — Question 6 7 marks

Exam BoardEdexcel
ModuleC1 (Core Mathematics 1)
Year2008
SessionJanuary
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCurve Sketching
TypeTwo stretches from same function
DifficultyModerate -0.8 This is a straightforward C1 transformations question requiring only recall of standard transformation rules: vertical stretch (multiply y-coordinates by 2), reflection in y-axis (negate x-coordinates), and horizontal translation (shift left by 2). No problem-solving or novel insight needed, just direct application of memorized transformation effects on key points.
Spec1.02w Graph transformations: simple transformations of f(x)

6. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{ba0ee180-4c22-49f7-8a8e-a7268828b067-07_693_676_370_632} \captionsetup{labelformat=empty} \caption{Figure 1}
\end{figure} Figure 1 shows a sketch of the curve with equation \(y = \mathrm { f } ( x )\). The curve crosses the \(x\)-axis at the points \(( 1,0 )\) and \(( 4,0 )\). The maximum point on the curve is \(( 2,5 )\).
In separate diagrams sketch the curves with the following equations.
On each diagram show clearly the coordinates of the maximum point and of each point at which the curve crosses the \(x\)-axis.
  1. \(y = 2 \mathrm { f } ( x )\),
  2. \(y = \mathrm { f } ( - x )\). The maximum point on the curve with equation \(y = \mathrm { f } ( x + a )\) is on the \(y\)-axis.
  3. Write down the value of the constant \(a\).

AnswerMarks
(a) Shape: Max in 1st quadrant and 2 intersections on positive \(x\)-axisB1
1 and 4 labelled (in correct place) or clearly stated as coordinatesB1
(2, 10) labelled or clearly statedB1
Total for (a): 3 marks
AnswerMarks
(b) Shape: Max in 2nd quadrant and 2 intersections on negative \(x\)-axisB1
\(-1\) and \(-4\) labelled (in correct place) or clearly stated as coordinatesB1
\((-2, 5)\) labelled or clearly statedB1
Total for (b): 3 marks
AnswerMarks Guidance
(c) \((a =) 2\)B1 May be implicit, i.e. \(f(x + 2)\)
Beware: The answer to part (c) may be seen on the first page.
Total for (c): 1 mark
Total: 7 marks
(a) Shape: Max in 1st quadrant and 2 intersections on positive $x$-axis | B1 |

1 and 4 labelled (in correct place) or clearly stated as coordinates | B1 |

(2, 10) labelled or clearly stated | B1 |

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

(b) Shape: Max in 2nd quadrant and 2 intersections on negative $x$-axis | B1 |

$-1$ and $-4$ labelled (in correct place) or clearly stated as coordinates | B1 |

$(-2, 5)$ labelled or clearly stated | B1 |

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

(c) $(a =) 2$ | B1 | May be implicit, i.e. $f(x + 2)$

Beware: The answer to part (c) may be seen on the first page.

**Total for (c): 1 mark**

**Total: 7 marks**

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6.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{ba0ee180-4c22-49f7-8a8e-a7268828b067-07_693_676_370_632}
\captionsetup{labelformat=empty}
\caption{Figure 1}
\end{center}
\end{figure}

Figure 1 shows a sketch of the curve with equation $y = \mathrm { f } ( x )$. The curve crosses the $x$-axis at the points $( 1,0 )$ and $( 4,0 )$. The maximum point on the curve is $( 2,5 )$.\\
In separate diagrams sketch the curves with the following equations.\\
On each diagram show clearly the coordinates of the maximum point and of each point at which the curve crosses the $x$-axis.
\begin{enumerate}[label=(\alph*)]
\item $y = 2 \mathrm { f } ( x )$,
\item $y = \mathrm { f } ( - x )$.

The maximum point on the curve with equation $y = \mathrm { f } ( x + a )$ is on the $y$-axis.
\item Write down the value of the constant $a$.
\end{enumerate}

\hfill \mbox{\textit{Edexcel C1 2008 Q6 [7]}}