Higher November 2019 Paper 5 Q17
17 Show that \(\sqrt[3]{a^4} \times \dfrac{1}{a}\) can be expressed as \(a^{\frac{1}{3}}\). [3]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| \(a^{\frac{4}{3}} \times a^{-1} = a^{\frac{4}{3} - 1} = a^{\frac{1}{3}}\) or \(a^{\frac{4}{3}} \div a = a^{\frac{4}{3} - 1} = a^{\frac{1}{3}}\) | 3 | B1 for \(a^{\frac{4}{3}}\) B1 for \(\left[\frac{1}{a} =\right] a^{-1}\) | e.g. \(a^{\frac{4}{3}} \times a^{-1} = a^{1/3}\) scores B1B1 only but \(a^{\frac{4}{3}} \times a^{-1} = a^{1/3}\) with \(\frac{4}{3} - 1 = \frac{1}{3}\) or arrow connecting \(\frac{4}{3}\) and –1 scores full marks. |