CAIE P2 2020 Specimen — Question 1 4 marks

Exam BoardCAIE
ModuleP2 (Pure Mathematics 2)
Year2020
SessionSpecimen
Marks4
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicFactor & Remainder Theorem
TypeSingle unknown constant
DifficultyModerate -0.8 This is a straightforward application of the Factor Theorem requiring substitution of x=-1 to find a constant, followed by polynomial division or substitution to find a remainder. Both parts are routine textbook exercises with no problem-solving insight required, making it easier than average but not trivial since it involves algebraic manipulation across two parts.
Spec1.02j Manipulate polynomials: expanding, factorising, division, factor theorem

1
  1. The polynomial \(2 x ^ { 3 } + a x ^ { 2 } - a x - 12\), where \(a\) is a constant, is denoted by \(\mathrm { p } ( x )\). It is given that \(( x + 1 )\) is a factor of \(\mathrm { p } ( x )\). Find the value of \(a\).
  2. When \(a\) has this value, find the remainder when \(\mathrm { p } ( x )\) is divided by \(( x + 3 )\).

Question 1:
Part 1(a):
AnswerMarks Guidance
AnswerMarks Guidance
Substitute \(x = -1\) and equate to zeroM1
Obtain answer \(a = 7\)A1
Total2
Part 1(b):
AnswerMarks Guidance
AnswerMarks Guidance
Substitute \(x = -3\) and evaluate expressionM1
Obtain answer 18A1
Total2
## Question 1:

**Part 1(a):**

| Answer | Marks | Guidance |
|--------|-------|----------|
| Substitute $x = -1$ and equate to zero | M1 | |
| Obtain answer $a = 7$ | A1 | |
| **Total** | **2** | |

**Part 1(b):**

| Answer | Marks | Guidance |
|--------|-------|----------|
| Substitute $x = -3$ and evaluate expression | M1 | |
| Obtain answer 18 | A1 | |
| **Total** | **2** | |

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1 (a) The polynomial $2 x ^ { 3 } + a x ^ { 2 } - a x - 12$, where $a$ is a constant, is denoted by $\mathrm { p } ( x )$. It is given that $( x + 1 )$ is a factor of $\mathrm { p } ( x )$.

Find the value of $a$.\\
(b) When $a$ has this value, find the remainder when $\mathrm { p } ( x )$ is divided by $( x + 3 )$.\\

\hfill \mbox{\textit{CAIE P2 2020 Q1 [4]}}