Higher November 2019 Paper 3 Q16
16 \(y\) is inversely proportional to the square of \(x\).
\(y = 8\) when \(x = 2.5\)
Find the negative value of \(x\) when \(y = \dfrac{8}{9}\) (3)
| Answer | Mark | Mark scheme |
|---|---|---|
| \(-7.5\) | M1 | for stating a correct relationship, eg \(y = \dfrac{k}{x^2}\) or \(8 = \dfrac{k}{2.5^2}\) |
| A1 | for \(k = 50\), could be seen in an equation | |
| A1 | \(-7.5\) oe |
Additional guidance
Accept \(y \propto \dfrac{k}{x^2}\) where \(k\) may be 1