Specimen 2020 Paper 1 Q13
13 Rearrange \(\quad t = \dfrac{3w^3 + a}{w^3 - 2} \quad\) to make \(w\) the subject. [5 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(t(w^3 - 2) = 3w^3 + a\) | M1 | |
| \(tw^3 - 2t = 3w^3 + a\) | M1dep | |
| \(tw^3 - 3w^3 = a + 2t\) | M1dep | |
| \(w^3(t - 3) = a + 2t\) or \(w^3 = \dfrac{a + 2t}{t - 3}\) | M1dep | |
| \(w = \sqrt[3]{\dfrac{a + 2t}{t - 3}}\) | A1 |