Edexcel P1 2023 January — Question 11

Exam BoardEdexcel
ModuleP1 (Pure Mathematics 1)
Year2023
SessionJanuary
TopicChain Rule

  1. A curve \(C\) has equation \(y = \mathrm { f } ( x ) , \quad x > 0\)
Given that
  • \(\mathrm { f } ^ { \prime \prime } ( x ) = 4 x + \frac { 1 } { \sqrt { x } }\)
  • the point \(P\) has \(x\) coordinate 4 and lies on \(C\)
  • the tangent to \(C\) at \(P\) has equation \(y = 3 x + 4\)
    1. find an equation of the normal to \(C\) at \(P\)
    2. find \(\mathrm { f } ( x )\), writing your answer in simplest form.