Edexcel D1 2019 June — Question 6

Exam BoardEdexcel
ModuleD1 (Decision Mathematics 1)
Year2019
SessionJune
TopicLinear Programming

6. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{87f0e571-e708-4ca9-adc7-4ed18e144d32-07_1502_1659_230_210} \captionsetup{labelformat=empty} \caption{Figure 4}
\end{figure} Figure 4 shows the constraints of a linear programming problem in \(x\) and \(y\), where \(R\) is the feasible region. The vertices of the feasible region are \(A ( 4,7 ) , B ( 5,3 ) , C ( - 1,5 )\) and \(D ( - 2,1 )\).
  1. Determine the inequality that defines the boundary of \(R\) that passes through vertices \(A\) and \(C\), leaving your answer with integer coefficients only. The objective is to maximise \(P = 5 x + y\)
  2. Find the coordinates of the optimal vertex and the corresponding value of \(P\). The objective is changed to maximise \(Q = k x + y\)
  3. If \(k\) can take any value, find the range of values of \(k\) for which \(A\) is the only optimal vertex.