CAIE P3 2019 June — Question 5

Exam BoardCAIE
ModuleP3 (Pure Mathematics 3)
Year2019
SessionJune
TopicComplex Numbers Arithmetic
TypeGiven one complex root, find all roots

5 Throughout this question the use of a calculator is not permitted. It is given that the complex number \(- 1 + ( \sqrt { } 3 ) \mathrm { i }\) is a root of the equation $$k x ^ { 3 } + 5 x ^ { 2 } + 10 x + 4 = 0$$ where \(k\) is a real constant.
  1. Write down another root of the equation.
  2. Find the value of \(k\) and the third root of the equation.