Date | May 2014 | Marks available | 4 | Reference code | 14M.1.hl.TZ2.8 |
Level | HL only | Paper | 1 | Time zone | TZ2 |
Command term | Find | Question number | 8 | Adapted from | N/A |
Question
The function f is defined by
f(x)={1−2x,34(x−2)2−3,x≤2x>2
Determine whether or not fis continuous.
The graph of the function g is obtained by applying the following transformations to the graph of f:
a reflection in the y–axis followed by a translation by the vector (20).
Find g(x).
Markscheme
1−2(2)=−3 and 34(2−2)2−3=−3 A1
both answers are the same, hence f is continuous (at x=2) R1
Note: R1 may be awarded for justification using a graph or referring to limits. Do not award A0R1.
[2 marks]
reflection in the y-axis
f(−x)={1+2x,34(x+2)2−3,x≥−2x<−2 (M1)
Note: Award M1 for evidence of reflecting a graph in y-axis.
translation (20)
g(x)={2x−3,34x2−3,x≥0x<0 (M1)A1A1
Note: Award (M1) for attempting to substitute (x−2) for x, or translating a graph along positive x-axis.
Award A1 for the correct domains (this mark can be awarded independent of the M1).
Award A1 for the correct expressions.
[4 marks]