Edexcel C2 — Question 12 6 marks

Exam BoardEdexcel
ModuleC2 (Core Mathematics 2)
Marks6
PaperDownload PDF ↗
TopicFactor & Remainder Theorem
TypeSingle polynomial, two remainder/factor conditions
DifficultyModerate -0.3 This is a straightforward application of the Remainder and Factor Theorems requiring students to substitute x=1 and x=-2 into f(x), then solve two simultaneous linear equations in a and b. While it involves multiple steps (6 marks total), the techniques are standard C2 content with no conceptual challenges or novel problem-solving required, making it slightly easier than average.
Spec1.02j Manipulate polynomials: expanding, factorising, division, factor theorem

$$f(x) = ax^3 + bx^2 - 7x + 14, \text{ where } a \text{ and } b \text{ are constants.}$$ Given that when \(f(x)\) is divided by \((x - 1)\) the remainder is 9,
  1. write down an equation connecting \(a\) and \(b\). [2]
Given also that \((x + 2)\) is a factor of \(f(x)\),
  1. Find the values of \(a\) and \(b\). [4]

$$f(x) = ax^3 + bx^2 - 7x + 14, \text{ where } a \text{ and } b \text{ are constants.}$$

Given that when $f(x)$ is divided by $(x - 1)$ the remainder is 9,

\begin{enumerate}[label=(\alph*)]
\item write down an equation connecting $a$ and $b$. [2]
\end{enumerate}

Given also that $(x + 2)$ is a factor of $f(x)$,

\begin{enumerate}[label=(\alph*)]
\setcounter{enumi}{1}
\item Find the values of $a$ and $b$. [4]
\end{enumerate}

\hfill \mbox{\textit{Edexcel C2  Q12 [6]}}