Date | May 2008 | Marks available | 4 | Reference code | 08M.1.sl.TZ2.5 |
Level | SL only | Paper | 1 | Time zone | TZ2 |
Command term | Describe and Find | Question number | 5 | Adapted from | N/A |
Question
Part of the graph of a function f is shown in the diagram below.
On the same diagram sketch the graph of y=−f(x) .
Let g(x)=f(x+3) .
(i) Find g(−3) .
(ii) Describe fully the transformation that maps the graph of f to the graph of g.
Markscheme
M1A1 N2
Note: Award M1 for evidence of reflection in x-axis, A1 for correct vertex and all intercepts approximately correct.
(i) g(−3)=f(0) (A1)
f(0)=−1.5 A1 N2
(ii) translation (accept shift, slide, etc.) of (−30) A1A1 N2
[4 marks]
Examiners report
This question was reasonably well done. Many recognized the graph of −f(x) as a reflection in a horizontal line, but fewer recognized the x-axis as the mirror line.
A fair number gave g(−3)=f(0) , but did not carry through to f(0)=−1.5 . The majority of candidates recognized that moving the graph of f(x) by 3 units to the left results in the graph of g(x) , but the language used to describe the transformation was often far from precise mathematically.