Edexcel P1 2020 January — Question 11

Exam BoardEdexcel
ModuleP1 (Pure Mathematics 1)
Year2020
SessionJanuary
TopicStandard Integrals and Reverse Chain Rule

11. A curve has equation \(y = \mathrm { f } ( x )\), where $$f ^ { \prime \prime } ( x ) = \frac { 6 } { \sqrt { x ^ { 3 } } } + x \quad x > 0$$ The point \(P ( 4 , - 50 )\) lies on the curve.
Given that \(\mathrm { f } ^ { \prime } ( x ) = - 4\) at \(P\),
  1. find the equation of the normal at \(P\), writing your answer in the form \(y = m x + c\), where \(m\) and \(c\) are constants,
    (3)
  2. find \(\mathrm { f } ( x )\).
    (8)
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