CAIE Further Paper 1 2020 June — Question 7 7 marks

Exam BoardCAIE
ModuleFurther Paper 1 (Further Paper 1)
Year2020
SessionJune
Marks7
TopicPolar coordinates

7 The curve \(C _ { 1 }\) has polar equation \(r = \theta \cos \theta\), for \(0 \leqslant \theta \leqslant \frac { 1 } { 2 } \pi\).
  1. The point on \(C _ { 1 }\) furthest from the line \(\theta = \frac { 1 } { 2 } \pi\) is denoted by \(P\). Show that, at \(P\), $$2 \theta \tan \theta - 1 = 0$$ and verify that this equation has a root between 0.6 and 0.7 .
    The curve \(C _ { 2 }\) has polar equation \(r = \theta \sin \theta\), for \(0 \leqslant \theta \leqslant \frac { 1 } { 2 } \pi\). The curves \(C _ { 1 }\) and \(C _ { 2 }\) intersect at the pole, denoted by \(O\), and at another point \(Q\).
  2. Find the polar coordinates of \(Q\), giving your answers in exact form.
  3. Sketch \(C _ { 1 }\) and \(C _ { 2 }\) on the same diagram.
  4. Find, in terms of \(\pi\), the area of the region bounded by the arc \(O Q\) of \(C _ { 1 }\) and the arc \(O Q\) of \(C _ { 2 }\). [7]
    If you use the following lined page to complete the answer(s) to any question(s), the question number(s) must be clearly shown.