Edexcel F1 2014 January — Question 4 9 marks

Exam BoardEdexcel
ModuleF1 (Further Pure Mathematics 1)
Year2014
SessionJanuary
Marks9
PaperDownload PDF ↗
TopicRoots of polynomials
TypeFactor theorem and finding roots
DifficultyStandard +0.3 This is a straightforward Further Pure question where two roots are given, requiring factorization of a quartic into (x+4)(x-3) times a quadratic, then solving that quadratic. Part (b) is routine plotting on an Argand diagram. While it's Further Maths content, the algebraic manipulation is mechanical and the question provides significant scaffolding by giving two roots explicitly.
Spec4.02j Cubic/quartic equations: conjugate pairs and factor theorem4.02k Argand diagrams: geometric interpretation

4. $$f ( x ) = x ^ { 4 } + 3 x ^ { 3 } - 5 x ^ { 2 } - 19 x - 60$$
  1. Given that \(x = - 4\) and \(x = 3\) are roots of the equation \(\mathrm { f } ( x ) = 0\), use algebra to solve \(\mathrm { f } ( x ) = 0\) completely.
  2. Show the four roots of \(\mathrm { f } ( x ) = 0\) on a single Argand diagram.

4.

$$f ( x ) = x ^ { 4 } + 3 x ^ { 3 } - 5 x ^ { 2 } - 19 x - 60$$
\begin{enumerate}[label=(\alph*)]
\item Given that $x = - 4$ and $x = 3$ are roots of the equation $\mathrm { f } ( x ) = 0$, use algebra to solve $\mathrm { f } ( x ) = 0$ completely.
\item Show the four roots of $\mathrm { f } ( x ) = 0$ on a single Argand diagram.
\end{enumerate}

\hfill \mbox{\textit{Edexcel F1 2014 Q4 [9]}}