Specimen 2020 Paper 2 Q14
14 Use the sine rule to work out the size of obtuse angle \(x\).
Not drawn accurately
[3 marks]| Answer | Mark | Comments |
|---|---|---|
| \(\dfrac{\sin x}{2y} = \dfrac{\sin 18}{y}\) | M1 | oe |
| \(\sin x = 2\sin 18\) or \(\sin x = [0.61, 0.62]\) or \(\sin^{-1}[0.61, 0.62]\) or 38.(17…) or 38.(2) | M1dep | oe eliminates \(y\) |
| 141.8… or 142 | A1 |