| Date | May 2009 | Marks available | 2 | Reference code | 09M.1.sl.TZ1.5 |
| Level | SL only | Paper | 1 | Time zone | TZ1 |
| Command term | Solve | Question number | 5 | Adapted from | N/A |
Question
Let \(f (x) = x^2 - 6x + 8\).
Factorise \(x^2 - 6x + 8\).
Hence, or otherwise, solve the equation \(x^2 - 6x + 8 = 0\).
Let \(g(x) = x + 3\).
Write down the solutions to the equation \(f (x) = g(x)\).
Markscheme
\( (x - 2)(x - 4)\) (A1)(A1) (C2)
[2 marks]
x = 2, x = 4 (A1)(ft)(A1)(ft) (C2)
[2 marks]
x = 0.807, x = 6.19 (A1)(A1) (C2)
Note: Award maximum of (A0)(A1) if coordinate pairs given.
OR
(M1) for an attempt to solve \(x^2 - 7x + 5 = 0\) via formula with correct values substituted. (M1)
\(x = \frac{{7 \pm \sqrt {29} }}{2}\) (A1) (C2)
[2 marks]
Examiners report
This was generally well answered, but a number seemed not to know the term “factorise”.
This was generally well answered.
This part proved problematic for many candidates. It was expected that the GDC was used, though many attempted an algebraic solution.
