4400 Higher June 2010 Paper 4 Q12
12
(a) 
(b) Find the three inequalites that define the unshaded region shown in the diagram below.
| Scheme | Marks |
|---|---|
| (grad =) \(-\frac{4}{8}\) oe (= −0.5) | B1 |
| \(Y\) intercept = 4 | B1 |
| \(y = \text{“}{-0.5}\text{”}x + 4\) | B1ft |
| (3) |
Notes
B1: −0.5 oe seen (can be implied from final answer)
B1: (correct \(y\) intercept)
B1ft: (ft grad only if \(v/h\) seen) (correct form for equation)
s.c. \(y = 0.5x + 4\) without working = B2
| Scheme | Marks |
|---|---|
| \(x \geqslant -1\) oe | B1 |
| \(y \geqslant x\) oe | B1 |
| \(y \leqslant \text{“}{-0.5}x + 4\text{”}\) oe | B1ft |
| (3) | |
| (6 marks) |
Notes
B1: accept \(x > -1\)
B1: accept \(y > x\)
B1ft: ft (a) accept \(y \lt \text{“}{-0.5}x + 4\text{”}\) must be a linear eqn in \(x\)
Ignore contradictions
sc B1 if all inequalities are facing the wrong way