Edexcel D1 — Question 1 7 marks

Exam BoardEdexcel
ModuleD1 (Decision Mathematics 1)
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicGraph Theory Fundamentals
TypePlanarity algorithm application
DifficultyStandard +0.3 This is a straightforward application of standard D1 algorithms: finding a Hamiltonian cycle (systematic trial) and then using it to construct a planar drawing. Both are routine procedures taught explicitly in the specification with no novel problem-solving required, making it slightly easier than average.
Spec7.02h Hamiltonian paths: and cycles7.02m Euler's formula: V + R = E + 2

1. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{6c6b7934-ab46-4a87-8a11-f99bf9a5d743-02_629_700_196_443} \captionsetup{labelformat=empty} \caption{Fig 1}
\end{figure}
  1. Find a Hamiltonian cycle for the graph shown in Figure 1.
  2. Starting with your cycle, construct a plane drawing of the graph, showing your method clearly.
    (5 marks)

AnswerMarks Guidance
(a) e.g. ABCDFEAB2
(b) Start with AC on inside, move BD outside, giving plane drawingM3 A2 (7)
**(a)** e.g. ABCDFEA | B2 |

**(b)** Start with AC on inside, move BD outside, giving plane drawing | M3 A2 | (7)

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1.

\begin{figure}[h]
\begin{center}
  \includegraphics[alt={},max width=\textwidth]{6c6b7934-ab46-4a87-8a11-f99bf9a5d743-02_629_700_196_443}
\captionsetup{labelformat=empty}
\caption{Fig 1}
\end{center}
\end{figure}
\begin{enumerate}[label=(\alph*)]
\item Find a Hamiltonian cycle for the graph shown in Figure 1.
\item Starting with your cycle, construct a plane drawing of the graph, showing your method clearly.\\
(5 marks)
\end{enumerate}

\hfill \mbox{\textit{Edexcel D1  Q1 [7]}}