CAIE P2 2024 March — Question 2 4 marks

Exam BoardCAIE
ModuleP2 (Pure Mathematics 2)
Year2024
SessionMarch
Marks4
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicModulus function
TypeSketch y=|linear| then solve equation or inequality (with unknown constants)
DifficultyModerate -0.3 Part (a) is routine modulus graph sketching requiring finding intercepts and the V-shape vertex. Part (b) requires geometric interpretation of when a line through (4,0) intersects the V-shape twice, which is a standard technique but requires some insight about gradient conditions. Overall slightly easier than average due to being a familiar modulus problem with only 4 marks total.
Spec1.02l Modulus function: notation, relations, equations and inequalities1.02m Graphs of functions: difference between plotting and sketching1.02s Modulus graphs: sketch graph of |ax+b|

  1. Sketch the graph of \(y = |3x - 7|\), stating the coordinates of the points where the graph meets the axes. [2]
  2. Hence find the set of values of the constant \(k\) for which the equation \(|3x - 7| = k(x - 4)\) has exactly two real roots. [2]

Question 2:

AnswerMarks Guidance
2(a)Draw V-shaped graph with vertex on positive x-axis B1
State (7, 0) and (0, 7)
AnswerMarks Guidance
3B1 Allow if only 7 and 7 shown on relevant axes.
3
2

AnswerMarks Guidance
2(b)State or imply that gradient of left-hand part of graph is –3 B1
State −3k0B1 Using < and not ⩽.
2
AnswerMarks Guidance
QuestionAnswer Marks
Question 2:
--- 2(a) ---
2(a) | Draw V-shaped graph with vertex on positive x-axis | B1
State (7, 0) and (0, 7)
3 | B1 | Allow if only 7 and 7 shown on relevant axes.
3
2
--- 2(b) ---
2(b) | State or imply that gradient of left-hand part of graph is –3 | B1
State −3k0 | B1 | Using < and not ⩽.
2
Question | Answer | Marks | Guidance
\begin{enumerate}[label=(\alph*)]
\item Sketch the graph of $y = |3x - 7|$, stating the coordinates of the points where the graph meets the axes. [2]
\item Hence find the set of values of the constant $k$ for which the equation $|3x - 7| = k(x - 4)$ has exactly two real roots. [2]
\end{enumerate}

\hfill \mbox{\textit{CAIE P2 2024 Q2 [4]}}