CAIE P2 2007 June — Question 1 4 marks

Exam BoardCAIE
ModuleP2 (Pure Mathematics 2)
Year2007
SessionJune
Marks4
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicModulus function
TypeSolve |linear| > |linear|
DifficultyModerate -0.3 This is a straightforward modulus inequality requiring students to consider cases based on critical points x = 3 and x = -2, then solve linear inequalities in each region. While it requires systematic case analysis, the algebraic manipulation is routine and the question is a standard textbook exercise with no novel insight needed, making it slightly easier than average.
Spec1.02l Modulus function: notation, relations, equations and inequalities

1 Solve the inequality \(| x - 3 | > | x + 2 |\).

AnswerMarks
Expand and solve a linear inequality, or equivalentM1
Obtain critical value \(\frac{1}{2}\)A1
State correct answer \(x < \frac{1}{2}\) (allow \(x \le \frac{1}{2}\))A1
OR
AnswerMarks
State a correct linear equation for the critical value, e.g. \(3 - x = x + 2\), or corresponding correct inequality, e.g. \(-(x-3) > (x+2)\)M1
Solve the linear equation, or inequalityM1
Obtain critical value \(\frac{1}{2}\)A1
State correct answer \(x < \frac{1}{2}\)A1
OR
AnswerMarks Guidance
Make recognisable sketches of both \(y =x-3 \) and \(y =
Obtain a critical value from the intersection of the graphsM1
Obtain critical value \(\frac{1}{2}\)A1
State final answer \(x < \frac{1}{2}\)A1 [4 marks]
Expand and solve a linear inequality, or equivalent | M1 | |
Obtain critical value $\frac{1}{2}$ | A1 | |
State correct answer $x < \frac{1}{2}$ (allow $x \le \frac{1}{2}$) | A1 | |

**OR**

State a correct linear equation for the critical value, e.g. $3 - x = x + 2$, or corresponding correct inequality, e.g. $-(x-3) > (x+2)$ | M1 | |
Solve the linear equation, or inequality | M1 | |
Obtain critical value $\frac{1}{2}$ | A1 | |
State correct answer $x < \frac{1}{2}$ | A1 | |

**OR**

Make recognisable sketches of both $y = |x-3|$ and $y = |x+2|$ on a single diagram | B1 | |
Obtain a critical value from the intersection of the graphs | M1 | |
Obtain critical value $\frac{1}{2}$ | A1 | |
State final answer $x < \frac{1}{2}$ | A1 | [4 marks] |
1 Solve the inequality $| x - 3 | > | x + 2 |$.

\hfill \mbox{\textit{CAIE P2 2007 Q1 [4]}}