Higher November 2018 Paper 4 Q20
20 The diagram shows a right-angled triangular prism ABCDEF.
Calculate angle AFB. [6]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| 20.9 or 20.89 or 20.886… or 21 with correct working | 6 | B1 for triangle AFB indicated e.g. drawn on diagram and M2 for [BF =] \(\sqrt{25^2 + 40^2}\) or 47.16[9…] or 47.17 or 47.2 or [AF =] \(\sqrt{25^2 + 40^2 + 18^2}\) or 50.48… or 50.5 or M1 for \(25^2 + 40^2\) [\(+\ 18^2\)] and M2 for e.g. \(\tan^{-1}\)(18 ÷ their 47.169…) or \(\sin^{-1}\)(18 ÷ their 50.48…) or M1 for [tan =] 18 ÷ their 47.169… or [sin =] 18 ÷ their 50.48… | their 47.169 should be an attempt at BF and their 50.48 should be an attempt at AF |