OCR MEI FP1 2011 June — Question 3 5 marks

Exam BoardOCR MEI
ModuleFP1 (Further Pure Mathematics 1)
Year2011
SessionJune
Marks5
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicRoots of polynomials
TypeRoots with given sum conditions
DifficultyStandard +0.8 This is a Further Maths question requiring systematic application of symmetric function relationships and algebraic manipulation. Students must use Vieta's formulas to connect the given conditions about sums of roots and their squares to the coefficients p and q, requiring the identity (α+β+γ)² = α²+β²+γ² + 2(αβ+βγ+γα). While methodical, it demands careful algebraic reasoning beyond standard A-level and is typical of FP1 difficulty.
Spec4.05a Roots and coefficients: symmetric functions

3 The equation \(x ^ { 3 } + p x ^ { 2 } + q x + 3 = 0\) has roots \(\alpha , \beta\) and \(\gamma\), where $$\begin{gathered} \alpha + \beta + \gamma = 4 \\ \alpha ^ { 2 } + \beta ^ { 2 } + \gamma ^ { 2 } = 6 \end{gathered}$$ Find \(p\) and \(q\).

3 The equation $x ^ { 3 } + p x ^ { 2 } + q x + 3 = 0$ has roots $\alpha , \beta$ and $\gamma$, where

$$\begin{gathered}
\alpha + \beta + \gamma = 4 \\
\alpha ^ { 2 } + \beta ^ { 2 } + \gamma ^ { 2 } = 6
\end{gathered}$$

Find $p$ and $q$.

\hfill \mbox{\textit{OCR MEI FP1 2011 Q3 [5]}}