OCR MEI Paper 3 2020 November — Question 12

Exam BoardOCR MEI
ModulePaper 3 (Paper 3)
Year2020
SessionNovember
TopicProduct & Quotient Rules

12
  1. Show that the only stationary point on the curve \(\mathrm { y } = \frac { \ln \mathrm { x } } { \mathrm { x } }\) occurs where \(x = \mathrm { e }\), as given in line 45.
  2. Show that the stationary point is a maximum.
  3. It follows from part (b) that, for any positive number \(a\) with \(a \neq \mathrm { e }\),
    \(\frac { \ln \mathrm { e } } { \mathrm { e } } > \frac { \ln a } { a }\).
    Use this fact to show that \(\mathrm { e } ^ { a } > a ^ { \mathrm { e } }\).