4MA0 Higher January 2018 Paper 4 Q15
15 \(P\) is inversely proportional to the square of \(d\).
\(P = 25.6\) when \(d = \dfrac{1}{8}\)
Find a formula for \(P\) in terms of \(d\).
(3)
| Scheme | Marks |
|---|---|
| \(P = \dfrac{k}{d^2}\) | M1 |
| \(25.6 = \dfrac{k}{\left(\dfrac{1}{8}\right)^2}\) oe or \(k = 0.4\) oe | M1 |
| \(P = \dfrac{2}{5d^2}\) | A1 |
| (3) |
Notes
M1: implies previous M1
A1: oe eg. \(P = \dfrac{0.4}{d^2}\)
allow \(P = \dfrac{k}{d^2}\) if \(k = 0.4\) oe stated