Higher June 2023 Paper 5 Q11
11 \(y\) is directly proportional to the square of \(x\).
Find the percentage decrease in \(y\) when \(x\) is decreased by 30%. [4]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 51 | 4 | M3 for \((1 - (1 - 0.3)^2)\) oe soi or M2 for \((1 - 0.3)^2\) oe soi or 0.49 or 49 or M1 for (1 – 0.3) oe soi or for \(y = kx^2\) oe or \(yk = x^2\) oe | \(\frac{51}{100}\) oe and –51 implies M3 For method soi if a value of \(x\) introduced e.g. if 100 used M2 for \(100 \times (1 - 0.3)^2\) oe M1 for \(100 \times (1 - 0.3)\) oe or 70 seen Not e.g. \(y \propto kx^2\) |