| Exam Board | OCR MEI |
|---|---|
| Module | C3 (Core Mathematics 3) |
| Marks | 6 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Function Transformations |
| Type | Describe transformation from graph |
| Difficulty | Moderate -0.3 This is a standard transformations question requiring identification of two transformations from graphs and writing the resulting function expressions. While it requires careful observation and correct application of transformation rules (particularly order of operations), it's a routine C3 topic with no novel problem-solving required. The 3 marks per part suggest straightforward execution once transformations are identified, making it slightly easier than average. |
| Spec | 1.02w Graph transformations: simple transformations of f(x) |
| Answer | Marks | Guidance |
|---|---|---|
| 3 | (i) | (One-way) stretch in y-direction, s.f. 2 |
| Answer | Marks |
|---|---|
| y = 2x1 | B1 |
| Answer | Marks |
|---|---|
| [3] | must specify s.f. and direction |
| o.e. e.g. y = 2x2y = 2(x1) | Allow ‘compress’, ‘squeeze’(for s.f. ½ ), but |
| Answer | Marks |
|---|---|
| (ii) | Reflection in x-axis or translation right ± or |
| Answer | Marks |
|---|---|
| y = 1 cos x | B1 |
| Answer | Marks |
|---|---|
| [3] | is B2 |
| Answer | Marks |
|---|---|
| needed) | Translations as above. |
Question 3:
3 | (i) | (One-way) stretch in y-direction, s.f. 2
or in x-direction s.f. ½
translation 1 to right (2 if followed by x-stretch)
y = 2x1 | B1
B1
B1
[3] | must specify s.f. and direction
o.e. e.g. y = 2x2y = 2(x1) | Allow ‘compress’, ‘squeeze’(for s.f. ½ ), but
not ‘enlarge’, ‘x-coordinates halved’, etc
Allow ‘shift’,’move’ or vector only, ‘right 1’
Don’t allow misreads (e.g. transforming
solid graph to dashed graph)
Award B1 for one of these seen, and a
second B1 if combined transformations are
correct
(ii) | Reflection in x-axis or translation right ± or
rotation of 180° [about O]
translation +1 in y-direction (− 1 if followed by
reflection in x-axis
y = 1 cos x | B1
B1
B1
[3] | is B2
1
allow 1 + cos(x ±) (bracket
needed) | Translations as above.
Reflection: must specify axis, allow ‘flip’
Rotation: condone no origin stated.
See additional notes for other possible
solutions.
Award B1 for any one of these seen, and a
second B1 if combined transformations are
correctEach of the graphs of $y = \text{f}(x)$ and $y = \text{g}(x)$ below is obtained using a sequence of two transformations applied to the corresponding dashed graph. In each case, state suitable transformations, and hence find expressions for f(x) and g(x).
\begin{enumerate}[label=(\roman*)]
\item
\includegraphics{figure_3i}
[3]
\item
\includegraphics{figure_3ii}
[3]
\end{enumerate}
\hfill \mbox{\textit{OCR MEI C3 Q3 [6]}}