OCR C2 — Question 8 10 marks

Exam BoardOCR
ModuleC2 (Core Mathematics 2)
Marks10
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicFactor & Remainder Theorem
TypeFind quotient and remainder by division
DifficultyModerate -0.3 This is a straightforward multi-part question testing routine algebraic manipulation and polynomial division. Part (i) is simple substitution, part (ii) is binomial expansion and simplification, and part (iii) is standard polynomial division or synthetic division—all mechanical procedures with no novel insight required. Slightly easier than average due to the guided structure.
Spec1.02j Manipulate polynomials: expanding, factorising, division, factor theorem

8. \(\mathrm { p } ( x ) = x ^ { 4 } - ( x - 2 ) ^ { 4 }\).
  1. Show that ( \(x - 1\) ) is a factor of \(\mathrm { p } ( x )\).
  2. Show that $$\mathrm { p } ( x ) = 8 x ^ { 3 } - 24 x ^ { 2 } + 32 x - 16$$
  3. Find the quotient and remainder when \(\mathrm { p } ( x )\) is divided by ( \(x + 1\) ).

Question 8:
Part (i):
AnswerMarks Guidance
Answer/WorkingMarks Notes
\(p(1) = 1^4 - (1-2)^4 = 1 - 1 = 0 \therefore (x-1)\) is a factorM1 A1
Part (ii):
AnswerMarks Guidance
Answer/WorkingMarks Notes
\(p(x) = x^4 - [x^4 + 4x^3(-2) + 6x^2(-2)^2 + 4x(-2)^3 + (-2)^4]\)M1 A1
\(= x^4 - [x^4 - 8x^3 + 24x^2 - 32x + 16]\)M1
\(= 8x^3 - 24x^2 + 32x - 16\)A1
Part (iii):
AnswerMarks Guidance
Answer/WorkingMarks Notes
Long division of \(8x^3 - 24x^2 + 32x - 16\) by \((x+1)\) giving \(8x^2 - 32x + 64\) remainder \(-80\)M2
quotient \(= 8x^2 - 32x + 64\)A1
remainder \(= -80\)A1 (10)
# Question 8:

## Part (i):
| Answer/Working | Marks | Notes |
|---|---|---|
| $p(1) = 1^4 - (1-2)^4 = 1 - 1 = 0 \therefore (x-1)$ is a factor | M1 A1 | |

## Part (ii):
| Answer/Working | Marks | Notes |
|---|---|---|
| $p(x) = x^4 - [x^4 + 4x^3(-2) + 6x^2(-2)^2 + 4x(-2)^3 + (-2)^4]$ | M1 A1 | |
| $= x^4 - [x^4 - 8x^3 + 24x^2 - 32x + 16]$ | M1 | |
| $= 8x^3 - 24x^2 + 32x - 16$ | A1 | |

## Part (iii):
| Answer/Working | Marks | Notes |
|---|---|---|
| Long division of $8x^3 - 24x^2 + 32x - 16$ by $(x+1)$ giving $8x^2 - 32x + 64$ remainder $-80$ | M2 | |
| quotient $= 8x^2 - 32x + 64$ | A1 | |
| remainder $= -80$ | A1 | **(10)** |

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8. $\mathrm { p } ( x ) = x ^ { 4 } - ( x - 2 ) ^ { 4 }$.\\
(i) Show that ( $x - 1$ ) is a factor of $\mathrm { p } ( x )$.\\
(ii) Show that

$$\mathrm { p } ( x ) = 8 x ^ { 3 } - 24 x ^ { 2 } + 32 x - 16$$

(iii) Find the quotient and remainder when $\mathrm { p } ( x )$ is divided by ( $x + 1$ ).\\

\hfill \mbox{\textit{OCR C2  Q8 [10]}}