Higher November 2016 Unit 1 Q11
11. Given that \(y\) is inversely proportional to \(x\), and that \(y = 4\) when \(x = 3\),
(a) find an expression for \(y\) in terms of \(x\), [3]
(b) use the expression you found in (a) to complete the following table. [2]
| \(x\) | 3 | 0·25 | |
|---|---|---|---|
| \(y\) | 4 | \(\dfrac{1}{5}\) |
| Scheme | Marks | Comments |
|---|---|---|
| \(y\) α \(1/x\) OR \(y = k/x\) | B1 | Allow \(y\) α k/\(x\) |
| \(4 = k/3\) OR \(k = 12\) | M1 | Must be in correct form, not a F.T. M1 implies B1. |
| \(y = 12/x\) | A1 | May be seen in part (b). Allow equivalent e.g. x = 12/y |
| Scheme | Marks | Comments | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| B2 | F.T. non-linear only. B1 for each value. |