| Exam Board | AQA |
|---|---|
| Module | Paper 2 (Paper 2) |
| Session | Specimen |
| Marks | 9 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Harmonic Form |
| Type | Range of squared harmonic expression |
| Difficulty | Standard +0.3 Part (a) requires expressing 3cos θ + 3sin θ in the form R cos(θ - α), which is a standard A-level technique, then identifying the transformations (stretch and translation). Part (b) applies this result to find max/min values using straightforward substitution. While it requires multiple steps and clear justification, both parts follow well-established procedures taught explicitly in the curriculum with no novel problem-solving required. |
| Spec | 1.02w Graph transformations: simple transformations of f(x)1.05f Trigonometric function graphs: symmetries and periodicities1.05n Harmonic form: a sin(x)+b cos(x) = R sin(x+alpha) etc |
| Answer | Marks | Guidance |
|---|---|---|
| 5(a) | Compares with Rcos() or | |
| Rsin() | AO3.1a | M1 |
| Answer | Marks | Guidance |
|---|---|---|
| allow them to solve the problem | AO3.1a | A1 |
| Obtains correct R | AO1.1b | A1 |
| Obtains correct | AO1.1b | A1 |
| Answer | Marks | Guidance |
|---|---|---|
| identify first transformation | AO3.2a | E1 |
| Answer | Marks | Guidance |
|---|---|---|
| identify second transformation | AO3.2a | E1 |
| (b) | Constructs a rigorous |
| Answer | Marks | Guidance |
|---|---|---|
| this mark) | AO2.1 | R1 |
| Answer | Marks | Guidance |
|---|---|---|
| Using ‘their’ values of R and | AO2.2a | A1F |
| Answer | Marks | Guidance |
|---|---|---|
| Using ‘their’ values of R and | AO2.2a | A1F |
| Total | 9 | |
| Q | Marking Instructions | AO |
Question 5:
--- 5(a) ---
5(a) | Compares with Rcos() or
Rsin() | AO3.1a | M1 | Rcos()
RsincosRsinsin
Rcos3 and Rsin3
R 18
4
3cos3sin 18cos
4
Which is a stretch in the y-direction
scale factor 18
and a translation 4
0
Identifies version which will
allow them to solve the problem | AO3.1a | A1
Obtains correct R | AO1.1b | A1
Obtains correct | AO1.1b | A1
Interprets ‘their’ equation to
identify first transformation | AO3.2a | E1
Interprets ‘their’ equation to
identify second transformation | AO3.2a | E1
(b) | Constructs a rigorous
mathematical argument, to find
either the least or greatest value
Only award if they have a
completely correct solution,
which is clear, easy to follow
and contains no slips (no FT for
this mark) | AO2.1 | R1 | 4(3cos3sin2
2
4 18cos
4
Least value occurs when
cos2 0
4
∴least value = 4
Greatest value occurs when
cos2 1
4
greatest value = 4 + 18
= 22
Deduces the least value
Using ‘their’ values of R and | AO2.2a | A1F
Deduces the greatest value
Using ‘their’ values of R and | AO2.2a | A1F
Total | 9
Q | Marking Instructions | AO | Marks | Typical Solution
\begin{enumerate}[label=(\alph*)]
\item Determine a sequence of transformations which maps the graph of $y = \cos \theta$ onto the graph of $y = 3\cos \theta + 3\sin \theta$
Fully justify your answer.
[6 marks]
\item Hence or otherwise find the least value and greatest value of
$$4 + (3\cos \theta + 3\sin \theta)^2$$
Fully justify your answer.
[3 marks]
\end{enumerate}
\hfill \mbox{\textit{AQA Paper 2 Q5 [9]}}