Edexcel F1 2024 June — Question 2

Exam BoardEdexcel
ModuleF1 (Further Pure Mathematics 1)
Year2024
SessionJune
TopicRoots of polynomials

  1. In this question you must show all stages of your working.
Solutions relying entirely on calculator technology are not acceptable. $$\mathrm { f } ( z ) = z ^ { 3 } - 13 z ^ { 2 } + 59 z + p \quad p \in \mathbb { Z }$$ Given that \(z = 3\) is a root of the equation \(f ( z ) = 0\)
  1. show that \(p = - 87\)
  2. Use algebra to determine the other roots of \(\mathrm { f } ( \mathrm { z } ) = 0\), giving your answers in simplest form. On an Argand diagram
    • the root \(z = 3\) is represented by the point \(P\)
    • the other roots of \(\mathrm { f } ( \mathrm { z } ) = 0\) are represented by the points \(Q\) and \(R\)
    • the number \(z = - 9\) is represented by the point \(S\)
    • Show on a single Argand diagram the positions of \(P , Q , R\) and \(S\)
    • Determine the perimeter of the quadrilateral \(P Q S R\), giving your answer as a simplified surd.