Edexcel Paper 2 2019 June — Question 11

Exam BoardEdexcel
ModulePaper 2 (Paper 2)
Year2019
SessionJune
TopicDifferentiation Applications

11. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{fa4afaf4-fe5d-4f3a-b3de-9600d5502a49-32_589_771_248_648} \captionsetup{labelformat=empty} \caption{Figure 8}
\end{figure} Figure 8 shows a sketch of the curve \(C\) with equation \(y = x ^ { x } , x > 0\)
  1. Find, by firstly taking logarithms, the \(x\) coordinate of the turning point of \(C\).
    (Solutions based entirely on graphical or numerical methods are not acceptable.) The point \(P ( \alpha , 2 )\) lies on \(C\).
  2. Show that \(1.5 < \alpha < 1.6\) A possible iteration formula that could be used in an attempt to find \(\alpha\) is $$x _ { n + 1 } = 2 x _ { n } ^ { 1 - x _ { n } }$$ Using this formula with \(x _ { 1 } = 1.5\)
  3. find \(x _ { 4 }\) to 3 decimal places,
  4. describe the long-term behaviour of \(x _ { n }\)