CAIE Further Paper 1 2020 November — Question 5

Exam BoardCAIE
ModuleFurther Paper 1 (Further Paper 1)
Year2020
SessionNovember
TopicPolar coordinates

5 The curve \(C\) has polar equation \(r = \ln ( 1 + \pi - \theta )\), for \(0 \leqslant \theta \leqslant \pi\).
  1. Sketch \(C\) and state the polar coordinates of the point of \(C\) furthest from the pole.
  2. Using the substitution \(u = 1 + \pi - \theta\), or otherwise, show that the area of the region enclosed by \(C\) and the initial line is $$\frac { 1 } { 2 } ( 1 + \pi ) \ln ( 1 + \pi ) ( \ln ( 1 + \pi ) - 2 ) + \pi$$
  3. Show that, at the point of \(C\) furthest from the initial line, $$( 1 + \pi - \theta ) \ln ( 1 + \pi - \theta ) - \tan \theta = 0$$ and verify that this equation has a root between 1.2 and 1.3.