Edexcel F1 2016 June — Question 9 9 marks

Exam BoardEdexcel
ModuleF1 (Further Pure Mathematics 1)
Year2016
SessionJune
Marks9
PaperDownload PDF ↗
TopicRoots of polynomials
TypeQuadratic with transformed roots
DifficultyStandard +0.8 This is a Further Maths question requiring systematic use of Vieta's formulas and algebraic manipulation to find sums and products of transformed roots. Part (a) is standard (using α+β and αβ to find power sums), but part (b) requires finding both sum and product of (α²+β) and (β²+α), which involves non-trivial algebraic manipulation and is more demanding than typical A-level questions.
Spec4.05a Roots and coefficients: symmetric functions4.05b Transform equations: substitution for new roots

9. The quadratic equation $$2 x ^ { 2 } + 4 x - 3 = 0$$ has roots \(\alpha\) and \(\beta\).
Without solving the quadratic equation,
  1. find the exact value of
    1. \(\alpha ^ { 2 } + \beta ^ { 2 }\)
    2. \(\alpha ^ { 3 } + \beta ^ { 3 }\)
  2. Find a quadratic equation which has roots ( \(\alpha ^ { 2 } + \beta\) ) and ( \(\beta ^ { 2 } + \alpha\) ), giving your answer in the form \(a x ^ { 2 } + b x + c = 0\), where \(a , b\) and \(c\) are integers.
    \includegraphics[max width=\textwidth, alt={}, center]{0b7ef4a1-51bf-4f0c-908a-7caf26a144dc-27_99_332_2622_1466}

9. The quadratic equation

$$2 x ^ { 2 } + 4 x - 3 = 0$$

has roots $\alpha$ and $\beta$.\\
Without solving the quadratic equation,
\begin{enumerate}[label=(\alph*)]
\item find the exact value of
\begin{enumerate}[label=(\roman*)]
\item $\alpha ^ { 2 } + \beta ^ { 2 }$
\item $\alpha ^ { 3 } + \beta ^ { 3 }$
\end{enumerate}\item Find a quadratic equation which has roots ( $\alpha ^ { 2 } + \beta$ ) and ( $\beta ^ { 2 } + \alpha$ ), giving your answer in the form $a x ^ { 2 } + b x + c = 0$, where $a , b$ and $c$ are integers.

\begin{center}

\end{center}

\includegraphics[max width=\textwidth, alt={}, center]{0b7ef4a1-51bf-4f0c-908a-7caf26a144dc-27_99_332_2622_1466}
\end{enumerate}

\hfill \mbox{\textit{Edexcel F1 2016 Q9 [9]}}