Edexcel C4 2014 January — Question 7

Exam BoardEdexcel
ModuleC4 (Core Mathematics 4)
Year2014
SessionJanuary
TopicParametric equations

7. The curve \(C\) has parametric equations $$x = 2 \cos t , \quad y = \sqrt { 3 } \cos 2 t , \quad 0 \leqslant t \leqslant \pi$$ where \(t\) is a parameter.
  1. Find an expression for \(\frac { \mathrm { d } y } { \mathrm {~d} x }\) in terms of \(t\). The point \(P\) lies on \(C\) where \(t = \frac { 2 \pi } { 3 }\)
    The line \(l\) is a normal to \(C\) at \(P\).
  2. Show that an equation for \(l\) is $$2 x - 2 \sqrt { 3 } y - 1 = 0$$ The line \(l\) intersects the curve \(C\) again at the point \(Q\).
  3. Find the exact coordinates of \(Q\). You must show clearly how you obtained your answers.
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