CAIE FP1 2018 June — Question 4

Exam BoardCAIE
ModuleFP1 (Further Pure Mathematics 1)
Year2018
SessionJune
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicRoots of polynomials

4 It is given that the equation $$x ^ { 3 } - 21 x ^ { 2 } + k x - 216 = 0$$ where \(k\) is a constant, has real roots \(a , a r\) and \(a r ^ { - 1 }\).
  1. Find the numerical values of the roots.
  2. Deduce the value of \(k\).

4 It is given that the equation

$$x ^ { 3 } - 21 x ^ { 2 } + k x - 216 = 0$$

where $k$ is a constant, has real roots $a , a r$ and $a r ^ { - 1 }$.\\
(i) Find the numerical values of the roots.\\

(ii) Deduce the value of $k$.\\

\hfill \mbox{\textit{CAIE FP1 2018 Q4}}