CAIE P3 2020 March — Question 1 4 marks

Exam BoardCAIE
ModuleP3 (Pure Mathematics 3)
Year2020
SessionMarch
Marks4
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicModulus function
TypeSketch y=|linear| then solve equation or inequality (numeric coefficients)
DifficultyModerate -0.8 Part (a) is a routine sketch of a basic translated modulus function requiring only recall of the V-shape centered at x=2. Part (b) involves solving a modulus inequality by considering cases (x≥2 and x<2), leading to straightforward linear inequalities—this is a standard textbook exercise with minimal problem-solving demand.
Spec1.05k Further identities: sec^2=1+tan^2 and cosec^2=1+cot^21.08h Integration by substitution

1
  1. Sketch the graph of \(y = | x - 2 |\).
  2. Solve the inequality \(| x - 2 | < 3 x - 4\).

Question 1:
Part 1(a):
AnswerMarks Guidance
AnswerMark Guidance
Make a recognisable sketch graph of \(y =x - 2 \)
Total1
Part 1(b):
Method 1:
AnswerMarks Guidance
AnswerMark Guidance
Find \(x\)-coordinate of intersection with \(y = 3x - 4\)M1
Obtain \(x = \dfrac{3}{2}\)A1
State final answer \(x > \dfrac{3}{2}\) onlyA1
Alternative Method 1:
AnswerMarks Guidance
AnswerMark Guidance
Solve the linear inequality \(3x - 4 > 2 - x\), or corresponding equationM1
Obtain critical value \(x = \dfrac{3}{2}\)A1
State final answer \(x > \dfrac{3}{2}\) onlyA1
Alternative Method 2:
AnswerMarks Guidance
AnswerMark Guidance
Solve the quadratic inequality \((x-2)^2 < (3x-4)^2\), or corresponding equationM1
Obtain critical value \(x = \dfrac{3}{2}\)A1
State final answer \(x > \dfrac{3}{2}\) onlyA1
Total3
## Question 1:

### Part 1(a):

| Answer | Mark | Guidance |
|--------|------|----------|
| Make a recognisable sketch graph of $y = |x - 2|$ | **B1** | |
| **Total** | **1** | |

---

### Part 1(b):

**Method 1:**

| Answer | Mark | Guidance |
|--------|------|----------|
| Find $x$-coordinate of intersection with $y = 3x - 4$ | **M1** | |
| Obtain $x = \dfrac{3}{2}$ | **A1** | |
| State final answer $x > \dfrac{3}{2}$ only | **A1** | |

**Alternative Method 1:**

| Answer | Mark | Guidance |
|--------|------|----------|
| Solve the linear inequality $3x - 4 > 2 - x$, or corresponding equation | **M1** | |
| Obtain critical value $x = \dfrac{3}{2}$ | **A1** | |
| State final answer $x > \dfrac{3}{2}$ only | **A1** | |

**Alternative Method 2:**

| Answer | Mark | Guidance |
|--------|------|----------|
| Solve the quadratic inequality $(x-2)^2 < (3x-4)^2$, or corresponding equation | **M1** | |
| Obtain critical value $x = \dfrac{3}{2}$ | **A1** | |
| State final answer $x > \dfrac{3}{2}$ only | **A1** | |
| **Total** | **3** | |
1
\begin{enumerate}[label=(\alph*)]
\item Sketch the graph of $y = | x - 2 |$.
\item Solve the inequality $| x - 2 | < 3 x - 4$.
\end{enumerate}

\hfill \mbox{\textit{CAIE P3 2020 Q1 [4]}}