Edexcel F1 Specimen — Question 4 12 marks

Exam BoardEdexcel
ModuleF1 (Further Pure Mathematics 1)
SessionSpecimen
Marks12
PaperDownload PDF ↗
TopicRoots of polynomials
TypeQuadratic with transformed roots
DifficultyStandard +0.3 This is a standard Further Maths roots transformation question requiring Vieta's formulas and algebraic manipulation. Part (a) is direct recall, part (b) is routine simplification using α+β and αβ, and part (c) follows a well-practiced method of finding sum and product of transformed roots. While it requires more steps than basic A-level, it's a textbook exercise with no novel insight needed.
Spec4.05a Roots and coefficients: symmetric functions4.05b Transform equations: substitution for new roots

  1. The quadratic equation
$$5 x ^ { 2 } - 4 x + 1 = 0$$ has roots \(\alpha\) and \(\beta\).
  1. Write down the value of \(\alpha + \beta\) and the value of \(\alpha \beta\).
  2. Show that \(\frac { \alpha } { \beta } + \frac { \beta } { \alpha } = \frac { 6 } { 5 }\)
  3. Find a quadratic equation with integer coefficients, which has roots $$\alpha + \frac { 1 } { \alpha } \text { and } \beta + \frac { 1 } { \beta }$$

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

$$5 x ^ { 2 } - 4 x + 1 = 0$$

has roots $\alpha$ and $\beta$.\\
(a) Write down the value of $\alpha + \beta$ and the value of $\alpha \beta$.\\
(b) Show that $\frac { \alpha } { \beta } + \frac { \beta } { \alpha } = \frac { 6 } { 5 }$\\
(c) Find a quadratic equation with integer coefficients, which has roots

$$\alpha + \frac { 1 } { \alpha } \text { and } \beta + \frac { 1 } { \beta }$$

\hfill \mbox{\textit{Edexcel F1  Q4 [12]}}