4MA0 Higher June 2015 Paper 3R Q9
9 Make \(r\) the subject of the formula \(A = 4\pi r^2\) where \(r\) is positive.
(2)
| Scheme | Marks |
|---|---|
| \(\dfrac{A}{4\pi} = r^2\) | M1 |
| \(\sqrt{\dfrac{A}{4\pi}}\) | A1 |
| (2) |
Notes
A1: accept equivalents eg. \(\dfrac{\sqrt{A\pi}}{2\pi}\), \(\dfrac{1}{2}\sqrt{\dfrac{A}{\pi}}\)