CAIE P3 2002 June — Question 10

Exam BoardCAIE
ModuleP3 (Pure Mathematics 3)
Year2002
SessionJune
TopicIntegration by Substitution

10
\includegraphics[max width=\textwidth, alt={}, center]{0f081749-4fe0-46e3-96c2-466e69cf49d3-4_620_894_338_687} The function f is defined by \(\mathrm { f } ( x ) = ( \ln x ) ^ { 2 }\) for \(x > 0\). The diagram shows a sketch of the graph of \(y = \mathrm { f } ( x )\). The minimum point of the graph is \(A\). The point \(B\) has \(x\)-coordinate e .
  1. State the \(x\)-coordinate of \(A\).
  2. Show that \(\mathrm { f } ^ { \prime \prime } ( x ) = 0\) at \(B\).
  3. Use the substitution \(x = \mathrm { e } ^ { u }\) to show that the area of the region bounded by the \(x\)-axis, the line \(x = \mathrm { e }\), and the part of the curve between \(A\) and \(B\) is given by $$\int _ { 0 } ^ { 1 } u ^ { 2 } \mathrm { e } ^ { u } \mathrm {~d} u .$$
  4. Hence, or otherwise, find the exact value of this area.