Higher June 2019 Paper 4 Q19
19 Solve this equation algebraically.
Give your solutions correct to 2 decimal places.
[4]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| −3.19 [0].52 with some correct algebraic working | 4 | M2 for correct substitution into the formula, allow one error e.g. \(\dfrac{-8 \pm \sqrt{8^2 - 4 \times 3 \times -5}}{2 \times 3}\) or for e.g. \(3\left[\left(x + \frac{8}{6}\right)^2 - \left(\frac{8}{6}\right)^2\right] - 5 = 0\) oe and \(x = \sqrt{\frac{5}{3} + \left(\frac{8}{6}\right)^2} - \frac{8}{6}\) oe or better or M1 for correct substitution into the formula, allow two errors or for e.g. \(3\left[\left(x + \frac{8}{6}\right)^2 - \left(\frac{8}{6}\right)^2\right] - 5 = 0\) oe or better and A1 for −3.19 or [0].52 or for both solutions correct but to more than 2dp. e.g. −3.189254… or 0.522588….. If 0 scored allow SC1 for two correct answers with no correct algebraic working. | |