Edexcel FP1 — Question 4 5 marks

Exam BoardEdexcel
ModuleFP1 (Further Pure Mathematics 1)
Marks5
PaperDownload PDF ↗
TopicComplex Numbers Arithmetic
TypeQuadratic from one complex root
DifficultyModerate -0.8 This is a standard Further Maths question testing the fundamental property that complex roots of real polynomials come in conjugate pairs, followed by routine application of Vieta's formulas or expansion. While it's FP1 content, it requires only direct recall of theory and basic arithmetic with no problem-solving insight needed.
Spec4.02g Conjugate pairs: real coefficient polynomials4.02i Quadratic equations: with complex roots

Given that \(2 + i\) is a root of the equation $$z^2 + bz + c = 0, \text{ where } b \text{ and } c \text{ are real constants,}$$
  1. write down the other root of the equation,
  2. find the value of \(b\) and the value of \(c\). [5]

Given that $2 + i$ is a root of the equation
$$z^2 + bz + c = 0, \text{ where } b \text{ and } c \text{ are real constants,}$$
\begin{enumerate}[label=(\roman*)]
\item write down the other root of the equation,
\item find the value of $b$ and the value of $c$. [5]
\end{enumerate}

\hfill \mbox{\textit{Edexcel FP1  Q4 [5]}}