Edexcel C4 2007 January — Question 3

Exam BoardEdexcel
ModuleC4 (Core Mathematics 4)
Year2007
SessionJanuary
TopicParametric equations

  1. A curve has parametric equations
$$x = 7 \cos t - \cos 7 t , y = 7 \sin t - \sin 7 t , \quad \frac { \pi } { 8 } < t < \frac { \pi } { 3 }$$
  1. Find an expression for \(\frac { \mathrm { d } y } { \mathrm {~d} x }\) in terms of \(t\). You need not simplify your answer.
  2. Find an equation of the normal to the curve at the point where \(t = \frac { \pi } { 6 }\). Give your answer in its simplest exact form.