AQA C4 2013 January — Question 4

Exam BoardAQA
ModuleC4 (Core Mathematics 4)
Year2013
SessionJanuary
TopicImplicit equations and differentiation

4
  1. A curve is defined by the equation \(x ^ { 2 } - y ^ { 2 } = 8\).
    1. Show that at any point \(( p , q )\) on the curve, where \(q \neq 0\), the gradient of the curve is given by \(\frac { \mathrm { d } y } { \mathrm {~d} x } = \frac { p } { q }\).
      (2 marks)
    2. Show that the tangents at the points \(( p , q )\) and \(( p , - q )\) intersect on the \(x\)-axis.
      (4 marks)
  2. Show that \(x = t + \frac { 2 } { t } , y = t - \frac { 2 } { t }\) are parametric equations of the curve \(x ^ { 2 } - y ^ { 2 } = 8\).
    (2 marks)