Edexcel C2 2007 June — Question 2 6 marks

Exam BoardEdexcel
ModuleC2 (Core Mathematics 2)
Year2007
SessionJune
Marks6
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicFactor & Remainder Theorem
TypeGiven factor, find all roots
DifficultyModerate -0.8 This is a straightforward application of the remainder theorem (substitute x=2) followed by routine polynomial factorisation using a given factor. Both parts require only direct recall of standard techniques with no problem-solving insight needed, making it easier than average but not trivial due to the algebraic manipulation required.
Spec1.02j Manipulate polynomials: expanding, factorising, division, factor theorem

$$f ( x ) = 3 x ^ { 3 } - 5 x ^ { 2 } - 16 x + 12$$
  1. Find the remainder when \(\mathrm { f } ( x )\) is divided by ( \(x - 2\) ). Given that \(( x + 2 )\) is a factor of \(\mathrm { f } ( x )\),
  2. factorise \(\mathrm { f } ( x )\) completely.

Question 2:
AnswerMarks Guidance
Answer/WorkingMarks Guidance
(a) \(f(2) = 24 - 20 - 32 + 12 = -16\)M1 A1 Attempt \(f(2)\) or \(f(-2)\); answer must appear in part (a)
(b) \((x+2)(3x^2 - 11x + 6)\)M1 A1 Division by \((x+2)\) to get quadratic with \(a\neq 0, b\neq 0\)
\((x+2)(3x-2)(x-3)\)M1 A1 Attempt to factorise quadratic; combining all 3 factors not required
Total: 6 marks
# Question 2:

| Answer/Working | Marks | Guidance |
|---|---|---|
| **(a)** $f(2) = 24 - 20 - 32 + 12 = -16$ | M1 A1 | Attempt $f(2)$ or $f(-2)$; answer must appear in part (a) |
| **(b)** $(x+2)(3x^2 - 11x + 6)$ | M1 A1 | Division by $(x+2)$ to get quadratic with $a\neq 0, b\neq 0$ |
| $(x+2)(3x-2)(x-3)$ | M1 A1 | Attempt to factorise quadratic; combining all 3 factors not required |

**Total: 6 marks**

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$$f ( x ) = 3 x ^ { 3 } - 5 x ^ { 2 } - 16 x + 12$$
\begin{enumerate}[label=(\alph*)]
\item Find the remainder when $\mathrm { f } ( x )$ is divided by ( $x - 2$ ).

Given that $( x + 2 )$ is a factor of $\mathrm { f } ( x )$,
\item factorise $\mathrm { f } ( x )$ completely.
\end{enumerate}

\hfill \mbox{\textit{Edexcel C2 2007 Q2 [6]}}