OCR H240/03 2020 November — Question 5

Exam BoardOCR
ModuleH240/03 (Pure Mathematics and Mechanics)
Year2020
SessionNovember
TopicParametric equations

5
\includegraphics[max width=\textwidth, alt={}, center]{373fa8e4-9c10-4fcf-9e00-e497161b4c6d-05_339_869_262_244} The diagram shows the curve \(C\) with parametric equations
\(x = \frac { 3 } { t } , y = t ^ { 3 } \mathrm { e } ^ { - 2 t }\), where \(t > 0\).
The maximum point on \(C\) is denoted by \(P\).
  1. Determine the exact coordinates of \(P\). The shaded region \(R\) is enclosed by the curve, the \(x\)-axis and the lines \(x = 1\) and \(x = 6\).
  2. Show that the area of \(R\) is given by $$\int _ { a } ^ { b } 3 t \mathrm { e } ^ { - 2 t } \mathrm {~d} t ,$$ where \(a\) and \(b\) are constants to be determined.
  3. Hence determine the exact area of \(R\).