Higher June 2023 Paper 2 Q11
11. Rearrange this formula to make \(y\) the subject.
\[a = 7\left(x + y^5\right) + 2\][4]
| Scheme | Marks | Comments |
|---|---|---|
| FT each step until second error | ||
| \(a = 7x + 7y^5 + 2\) | B1 | Expand brackets |
| \(a - 7x - 2 = 7y^5\) | B1 | Isolate \(7y^5\) |
| \(\dfrac{a - 7x - 2}{7} = y^5\) | B1 | Isolate \(y^5\) |
| \(y = \sqrt[5]{\dfrac{a - 7x - 2}{7}}\) | B1 | Mark final answer |
Alternative method
| Scheme | Marks | Comments |
|---|---|---|
| FT each step until second error | ||
| \(a - 2 = 7(x + y^5)\) | B1 | |
| \(\dfrac{a-2}{7} = x + y^5\) or \(a - 2 = 7x + 7y^5\) | B1 | |
| \(\dfrac{a-2}{7} - x = y^5\) or \(\dfrac{a-2-7x}{7} = y^5\) | B1 | |
| \(y = \sqrt[5]{\dfrac{a-2}{7} - x}\) or \(y = \sqrt[5]{\dfrac{a-2-7x}{7}}\) | B1 | Mark final answer |
| (4) |