Edexcel Paper 1 2019 June — Question 14

Exam BoardEdexcel
ModulePaper 1 (Paper 1)
Year2019
SessionJune
TopicSmall angle approximation

  1. The curve \(C\), in the standard Cartesian plane, is defined by the equation
$$x = 4 \sin 2 y \quad \frac { - \pi } { 4 } < y < \frac { \pi } { 4 }$$ The curve \(C\) passes through the origin \(O\)
  1. Find the value of \(\frac { \mathrm { d } y } { \mathrm {~d} x }\) at the origin.
    1. Use the small angle approximation for \(\sin 2 y\) to find an equation linking \(x\) and \(y\) for points close to the origin.
    2. Explain the relationship between the answers to (a) and (b)(i).
  2. Show that, for all points \(( x , y )\) lying on \(C\), $$\frac { \mathrm { d } y } { \mathrm {~d} x } = \frac { 1 } { a \sqrt { b - x ^ { 2 } } }$$ where \(a\) and \(b\) are constants to be found.