Higher June 2017 Paper 1 Q4
4
The area of square \(ABCD\) is 10 cm2.
Show that \(x^2 + 6x = 1\) (3)
| Answer | Mark | Notes |
|---|---|---|
| \(x^2 + 6x = 1\) | M1 | writes the area using algebraic terms e.g. \((x + 3) \times (x + 3)\) or at least two correct area expressions which may be written on the diagram or \(x\) given as \(\sqrt{10} - 3\) |
| M1 | expands and includes the given 10 e.g. \(x^2 + 3x + 3x + 9 = 10\); condone one error in the four terms when expanding or \(10 - 3\sqrt{10} - 3\sqrt{10} + 9 + 6\sqrt{10} - 18\ (=1)\) condone 1 error in the 6 terms | |
| A1 | rearranges to give the given equation or shows surd expression simplifies to 1 |