WJEC Unit 3 2023 June — Question 7 10 marks

Exam BoardWJEC
ModuleUnit 3 (Unit 3)
Year2023
SessionJune
Marks10
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicModulus function
TypeSketch two |linear| functions and solve related equation/inequality
DifficultyModerate -0.3 Part (a) is trivial algebra (equating two linear functions). Part (b) requires sketching modulus functions and finding intersections, which is standard A-level content. Part (c) involves calculating area between modulus graphs using integration or geometry, requiring careful consideration of regions but following routine methods. The 10-mark total and multi-step nature elevate it slightly, but all techniques are standard textbook exercises with no novel insight required.
Spec1.02i Represent inequalities: graphically on coordinate plane1.02l Modulus function: notation, relations, equations and inequalities1.02s Modulus graphs: sketch graph of |ax+b|

  1. The graphs of \(y = 5x - 3\) and \(y = 2x + 3\) intersect at the point A. Show that the coordinates of A are \((2, 7)\). [2]
  2. On the same set of axes, sketch the graphs of \(y = |5x - 3|\) and \(y = |2x + 3|\), clearly indicating the coordinates of the points of intersection of the two graphs and the points where the graphs touch the \(x\)-axis. [4]
  3. Calculate the area of the region satisfying the inequalities $$y \geqslant |5x - 3| \quad \text{and} \quad y \leqslant |2x + 3|.$$ [4]

\begin{enumerate}[label=(\alph*)]
\item The graphs of $y = 5x - 3$ and $y = 2x + 3$ intersect at the point A. Show that the coordinates of A are $(2, 7)$. [2]

\item On the same set of axes, sketch the graphs of $y = |5x - 3|$ and $y = |2x + 3|$, clearly indicating the coordinates of the points of intersection of the two graphs and the points where the graphs touch the $x$-axis. [4]

\item Calculate the area of the region satisfying the inequalities
$$y \geqslant |5x - 3| \quad \text{and} \quad y \leqslant |2x + 3|.$$ [4]
\end{enumerate}

\hfill \mbox{\textit{WJEC Unit 3 2023 Q7 [10]}}