Higher June 2017 Paper 2 Q7
7 Use trigonometry to work out the length \(x\).
Not drawn accurately
[2 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(\sin 72 = \dfrac{x}{8}\) or \(8 \times \sin 72\) or \(\cos (90 - 72) = \dfrac{x}{8}\) or \(8 \times \cos (90 - 72)\) or \(\dfrac{x}{\sin 72} = \dfrac{8}{\sin 90}\) or \(\dfrac{\sin 72}{x} = \dfrac{\sin 90}{8}\) | M1 | oe eg \(8 \cos 72\) or 2.47… or 2.5 and \(\sqrt{8^2 - (8\cos 72)^2}\) |
| [7.6, 7.61] | A1 |
Additional guidance
| If trigonometry and Pythagoras are used it must be a fully correct method that would lead to the correct value of \(x\) | |
| Accept \(\sin 72 \times 8\) | M1 |
| Accept opp or o for \(x\) \(\;\) eg \(\sin 72 = \dfrac{\text{opp}}{8}\) | M1 |
| \(\sin = \dfrac{x}{8}\) or \(\sin \theta = \dfrac{x}{8}\) (unless recovered) | M0 |
| Answer coming from scale drawing | M0A0 |
| Answer in range seen followed by 7 or 8 | M1A1 |