October 2021 Paper 3 Q8
8 For a particular value of \(a\), the curve \(y = \dfrac{a}{x^2}\) passes through the point \((3, 1)\).
Find the coordinates of all the other points on the curve where both the \(x\)-coordinate and the \(y\)-coordinate are integers. [3]
| Scheme | Marks | AO |
|---|---|---|
| \(a = 9\) | M1 | 3.1a |
| \((-3, 1),\ (1, 9),\ (-1, 9)\) | A2 | 1.1 2.2a |
| [3] |
Notes
M1: Implied by any of the points
A2: A2 for all three points.
A1 for one correct point
Ignore \((3, 1)\)
If other incorrect points A1 max