CAIE P2 2005 June — Question 1 4 marks

Exam BoardCAIE
ModuleP2 (Pure Mathematics 2)
Year2005
SessionJune
Marks4
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicModulus function
TypeSolve |linear| > |linear|
DifficultyStandard +0.3 This is a straightforward modulus inequality requiring consideration of cases based on sign changes at x=0 and x=2/3. While it involves multiple cases and some algebraic manipulation, it's a standard textbook exercise testing routine application of modulus properties without requiring novel insight or extended reasoning.
Spec1.02l Modulus function: notation, relations, equations and inequalities1.02t Solve modulus equations: graphically with modulus function

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

AnswerMarks
State or imply non-modular inequality \(x^2 > (3x - 2)^2\), or corresponding equationM1
Expand and make reasonable solution attempt at 2- or 3-term quadratic, or equivalentM1
Obtain critical values \(\frac{1}{2}\) and \(1\)A1
State correct answer \(\frac{1}{2} < x < 1\)A1
OR
AnswerMarks
State one correct linear equation for a critical valueM1
State two equations separatelyA1
Obtain critical values \(\frac{1}{2}\) and \(1\)A1
State correct answer \(\frac{1}{2} < x < 1\)A1
OR
AnswerMarks
State one critical value from a graphical method or inspection or by solving a linear inequalityB1
State the other critical value correctlyB2
State correct answer \(\frac{1}{2} < x < 1\)B1
Total: 4 marks
| State or imply non-modular inequality $x^2 > (3x - 2)^2$, or corresponding equation | M1 |
| Expand and make reasonable solution attempt at 2- or 3-term quadratic, or equivalent | M1 |
| Obtain critical values $\frac{1}{2}$ and $1$ | A1 |
| State correct answer $\frac{1}{2} < x < 1$ | A1 |

**OR**

| State one correct linear equation for a critical value | M1 |
| State two equations separately | A1 |
| Obtain critical values $\frac{1}{2}$ and $1$ | A1 |
| State correct answer $\frac{1}{2} < x < 1$ | A1 |

**OR**

| State one critical value from a graphical method or inspection or by solving a linear inequality | B1 |
| State the other critical value correctly | B2 |
| State correct answer $\frac{1}{2} < x < 1$ | B1 |

**Total: 4 marks**

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1 Solve the inequality $| x | > | 3 x - 2 |$.

\hfill \mbox{\textit{CAIE P2 2005 Q1 [4]}}