AQA AS Paper 1 2021 June — Question 5 6 marks

Exam BoardAQA
ModuleAS Paper 1 (AS Paper 1)
Year2021
SessionJune
Marks6
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicCurve Sketching
TypeSketch with inequalities or regions
DifficultyModerate -0.3 This is a straightforward curve sketching question requiring students to find intercepts (x=a with multiplicity 2, x=3, y=-3a²) and sketch a cubic with standard shape. Part (b) follows directly from the sketch by reading off where y>0. While it requires multiple steps and understanding of repeated roots, it's a standard AS-level exercise with no novel problem-solving required, making it slightly easier than average.
Spec1.02g Inequalities: linear and quadratic in single variable1.02h Express solutions: using 'and', 'or', set and interval notation1.02n Sketch curves: simple equations including polynomials

  1. Sketch the curve $$y = (x - a)^2(3 - x) \quad \text{where } 0 < a < 3$$ indicating the coordinates of the points where the curve and the axes meet. [4 marks] \includegraphics{figure_5}
  2. Hence, solve $$(x - a)^2(3 - x) > 0$$ giving your answer in set notation form. [2 marks]

Question 5:

AnswerMarks Guidance
5(a)Draws a correctly orientated
cubic graph1.1b B1
Draws a graph cutting x axis at
(3, 0) labelled.
AnswerMarks Guidance
Condone omission of 01.1b B1
Draws a graph meeting x axis at
(a, 0) labelled.
AnswerMarks Guidance
Condone omission of 02.2a B1
Draws a graph cutting y axis at
(0, 3a2) labelled.
AnswerMarks Guidance
Condone omission of 01.1b B1
Subtotal4
QMarking instructions AO

AnswerMarks Guidance
5(b)Deduces that x < a or a < x < 3
OE2.2a M1
⋃ { 𝑥𝑥: 𝑎𝑎 < 𝑥𝑥 < 3}
Expresses answer in set
notation.
AnswerMarks Guidance
Or2.5 R1
{𝑥𝑥: 0 < 𝑥𝑥 < 3, 𝑥𝑥 ≠S𝑎𝑎u}btotal2
Question Total6
QMarking instructions AO
Question 5:
--- 5(a) ---
5(a) | Draws a correctly orientated
cubic graph | 1.1b | B1 | y = 0 at 3 and a (twice)
Draws a graph cutting x axis at
(3, 0) labelled.
Condone omission of 0 | 1.1b | B1
Draws a graph meeting x axis at
(a, 0) labelled.
Condone omission of 0 | 2.2a | B1
Draws a graph cutting y axis at
(0, 3a2) labelled.
Condone omission of 0 | 1.1b | B1
Subtotal | 4
Q | Marking instructions | AO | Marks | Typical solution
--- 5(b) ---
5(b) | Deduces that x < a or a < x < 3
OE | 2.2a | M1 | { x: x < a }
⋃ { 𝑥𝑥: 𝑎𝑎 < 𝑥𝑥 < 3}
Expresses answer in set
notation.
Or | 2.5 | R1
{𝑥𝑥: 0 < 𝑥𝑥 < 3, 𝑥𝑥 ≠S𝑎𝑎u}btotal | 2
Question Total | 6
Q | Marking instructions | AO | Marks | Typical solution
\begin{enumerate}[label=(\alph*)]
\item Sketch the curve
$$y = (x - a)^2(3 - x) \quad \text{where } 0 < a < 3$$
indicating the coordinates of the points where the curve and the axes meet.
[4 marks]

\includegraphics{figure_5}

\item Hence, solve
$$(x - a)^2(3 - x) > 0$$
giving your answer in set notation form.
[2 marks]
\end{enumerate}

\hfill \mbox{\textit{AQA AS Paper 1 2021 Q5 [6]}}