Edexcel F1 2022 June — Question 5 10 marks

Exam BoardEdexcel
ModuleF1 (Further Pure Mathematics 1)
Year2022
SessionJune
Marks10
PaperDownload PDF ↗
TopicRoots of polynomials
TypeQuadratic with transformed roots
DifficultyStandard +0.8 This is a multi-part Further Maths question requiring systematic application of Vieta's formulas and transformation of roots. Part (a) is routine recall, parts (b)(i)-(ii) require standard algebraic manipulation with symmetric functions, but part (c) demands finding sum and product of asymmetric transformed roots (α³-β and β³-α), requiring careful algebraic work and insight into how to express these in terms of elementary symmetric functions. The extended multi-step nature and the non-standard root transformation elevate this above typical A-level questions.
Spec4.05a Roots and coefficients: symmetric functions4.05b Transform equations: substitution for new roots

  1. The quadratic equation
$$2 x ^ { 2 } - 3 x + 5 = 0$$ has roots \(\alpha\) and \(\beta\) Without solving the equation,
  1. write down the value of \(( \alpha + \beta )\) and the value of \(\alpha \beta\)
  2. determine the value of
    1. \(\alpha ^ { 2 } + \beta ^ { 2 }\)
    2. \(\alpha ^ { 3 } + \beta ^ { 3 }\)
  3. find a quadratic equation which has roots $$\left( \alpha ^ { 3 } - \beta \right) \text { and } \left( \beta ^ { 3 } - \alpha \right)$$ giving your answer in the form \(p x ^ { 2 } + q x + r = 0\) where \(p , q\) and \(r\) are integers to be determined.

\begin{enumerate}
  \item The quadratic equation
\end{enumerate}

$$2 x ^ { 2 } - 3 x + 5 = 0$$

has roots $\alpha$ and $\beta$\\
Without solving the equation,\\
(a) write down the value of $( \alpha + \beta )$ and the value of $\alpha \beta$\\
(b) determine the value of\\
(i) $\alpha ^ { 2 } + \beta ^ { 2 }$\\
(ii) $\alpha ^ { 3 } + \beta ^ { 3 }$\\
(c) find a quadratic equation which has roots

$$\left( \alpha ^ { 3 } - \beta \right) \text { and } \left( \beta ^ { 3 } - \alpha \right)$$

giving your answer in the form $p x ^ { 2 } + q x + r = 0$ where $p , q$ and $r$ are integers to be determined.

\hfill \mbox{\textit{Edexcel F1 2022 Q5 [10]}}