| Date | May 2010 | Marks available | 4 | Reference code | 10M.1.sl.TZ1.1 |
| Level | SL only | Paper | 1 | Time zone | TZ1 |
| Command term | Find | Question number | 1 | Adapted from | N/A |
Question
Let \(f(x) = 8x - 2{x^2}\) . Part of the graph of f is shown below.
Find the x-intercepts of the graph.
(i) Write down the equation of the axis of symmetry.
(ii) Find the y-coordinate of the vertex.
Markscheme
evidence of setting function to zero (M1)
e.g. \(f(x) = 0\) , \(8x = 2{x^2}\)
evidence of correct working A1
e.g. \(0 = 2x(4 - x)\) , \(\frac{{ - 8 \pm \sqrt {64} }}{{ - 4}}\)
x-intercepts are at 4 and 0 (accept (4, 0) and (0, 0) , or \(x = 4\) , \(x = 0\) ) A1A1 N1N1
[4 marks]
(i) \(x = 2\) (must be equation) A1 N1
(ii) substituting \(x = 2\) into \(f(x)\) (M1)
\(y = 8\) A1 N2
[3 marks]
Examiners report
This question was answered well by most candidates.
This question was answered well by most candidates. Some did not give an equation for their axis of symmetry.
